Removable terminal pin connector for an active electronics circuit board for use in an implantable medical device

ABSTRACT

A hermetic feedthrough terminal pin connector for an active implantable medical device (AIMD) includes an electrical insulator hermetically sealed to an opening of an electrically conductive ferrule. A feedthrough terminal pin is hermetically sealed to and disposed through the insulator, the feedthrough terminal pin extending outwardly beyond the insulator on the inside of the casing of the AIMD. A circuit board is disposed on the inside of the casing of the AIMD. A terminal pin connector includes: an electrically conductive connector housing disposed on the circuit board, wherein the connector housing is electrically connected to at least one electrical circuit disposed on the circuit board; and at least one electrically conductive prong supported by the connector housing, the at least one prong contacting and compressed against the feedthrough terminal pin, the at least one prong making a removable electrical connection.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application Is a continuation-in-part application claiming priorityto U.S. patent application Ser. No. 15/628,741, filed on Jun. 21, 2017;now U.S. Pat. No. 10,587,073, which claims priority to U.S. patentapplication Ser. No. 14/747,582, filed on Jun. 23, 2015, now U.S. Pat.No. 9,692,173; which claims priority to U.S. patent application Ser. No.13/487,293, filed on Jun. 4, 2012, now U.S. Pat. No. 9,065,224; whichclaims priority to U.S. provisional application Ser. No. 61/492,828,filed on Jun. 3, 2011; the contents of which are fully incorporatedherein by these references.

DESCRIPTION Field of the Invention

This invention relates generally to a hermetic feedthrough terminal pinassembly, usually of the type incorporating a filter capacitor, for usein implantable medical devices such as cardiac pacemakers, cardioverterdefibrillators, and the like, to facilitate connection of thefeedthrough terminal pin to a circuit board within the implantablemedical device. More specifically, this invention relates to a removableconnector assembly comprising various novel structures taught hereinthat allow rework and/or replacement of various electrical components,if necessary, after testing discovers a potential malfunction orproblem, thereby saving time, expense and resources.

Background of the Invention

Feedthrough assemblies are generally well known by those skilled in theart of active implantable medical devices for use in connectingelectrical signals through the housing, can, casing or case of anelectronic instrument or device. For example, in an implantable medicaldevice, such as a cardiac pacemaker, defibrillator, or neurostimulator,the feedthrough assembly comprises one or more conductive terminal pinssupported by an insulator structure for passage of electrical signalsfrom the exterior to the interior of the medical device. The conductiveterminals are fixed into place using a metallization and gold brazeprocess, which provides a hermetic seal between the pin and insulativematerial.

Conventionally, the ends of the terminal pin distal ends are permanentlyelectrically connected directly within the active implantable medicaldevice to circuit boards inside the casing or to an AIMD header blockoutside the casing. As an example, the terminal pin distal end may beelectrically connected directly to an electrical circuit board residingwithin the device by using a soldering or welding attachment process.This connection is readily achievable utilizing platinum or platinumalloy based terminal pins of the prior art.

However, once this electrical connection is made, it is very hard toreplace various components if a problem is detected during testing. Thepresent invention, therefore, facilitates the testing and removal and/orexchange of various electrical components, such as the circuit board, sothat significant cost, time and resources can be saved.

SUMMARY OF THE INVENTION

Referring generally to FIGS. 1 to 9, an exemplary embodiment of thepresent invention includes a hermetic feedthrough terminal pin connectorassembly for an active implantable medical device (AIMD) comprising: a)an electrically conductive ferrule configured to hermetically seal anopening of a casing of the AIMD, the ferrule configured to prevent aleakage of a body fluid in a human implant application to an inside ofthe casing of the AIMD; b) an electrical insulator hermetically sealinga ferrule opening, the insulator configured to prevent the leakage ofthe body fluid in the human implant application to the inside of thecasing of the AIMD; c) a feedthrough terminal pin hermetically sealed toand disposed through the insulator, the feedthrough terminal pinextending outwardly beyond the insulator on the inside of the casing ofthe AIMD; d) a circuit board disposed on the inside of the casing of theAIMD; and e) a terminal pin connector, comprising: i) an electricallyconductive connector housing disposed on the circuit board, wherein theconnector housing is electrically connected to at least one electricalcircuit disposed on the circuit board; and ii) at least one electricallyconductive prong supported by the connector housing, the at least oneprong contacting and compressed against the feedthrough terminal pinextending outwardly beyond the insulator on the inside of the casing ofthe AIMD. Circuit boards include multilayer boards, multilayer aluminaboards, printed circuit boards (otherwise known as PCBs or printedcircuits), FR-4 or FR4 boards and the like.

In other exemplary embodiments, the at least one prong may comprise atleast two prongs, each prong contacting and compressed against thefeedthrough terminal pin extending outwardly beyond the insulator on theinside of the casing of the AIMD. Alternatively, the at least one prongmay comprise a plurality of prongs, each prong of the plurality ofprongs contacting and compressed against the feedthrough terminal pinextending outwardly beyond the insulator on the inside of the casing ofthe AIMD.

The connector housing may be electrically connected to the at least oneelectrical circuit with a solder, a braze, an electrically conductiveadhesive or a weld.

The terminal pin connector may be configured to allow multipleinsertions and retractions of the feedthrough terminal pin extendingoutwardly beyond the insulator on the inside of the casing of the AIMDwithout affecting reliability and enabling rework or pre-assemblytesting.

The connector housing may comprise a housing sidewall defining a housingopening surrounded by a housing inner surface, wherein the at least oneprong comprises at least two prongs that extend from a base, the basesupported by the housing inner surface, wherein the at least two prongsare angled inwardly towards a central axis that extends longitudinallythrough a through-bore of the base, wherein the feedthrough terminal pinextending outwardly beyond the insulator on the inside of the casing ofthe AIMD is disposed through the through-bore of the base. The housingsidewall may comprise at least one planar surface attached to andcontacting the circuit board.

A ground terminal pin may be electrically connected to the ferrule andinclude a second terminal pin connector disposed on the circuit board,wherein the ground terminal pin is electrically connected to the secondterminal pin connector. A second ground terminal pin may be electricallyconnected to the ferrule and include a third terminal pin connectordisposed on the circuit board, wherein the second ground terminal pin iselectrically connected to the third terminal pin connector.

A feedthrough capacitor may be included having at least one activeelectrode plate disposed apart and parallel to at least one groundelectrode plate within a capacitor dielectric, wherein the at least oneactive electrode plate is electrically connected to the feedthroughterminal pin and the at least one ground electrode plate is electricallyconnected to the ferrule, wherein the feedthrough terminal pin extendsoutwardly beyond the feedthrough capacitor on the inside of the casingof the AIMD.

Another exemplary embodiment of the present invention includes aterminal pin connector assembly for an active implantable medical device(AIMD), the terminal pin connector assembly comprising: a) a circuitboard configured to be disposed on an inside of a casing of the AIMD;and b) a terminal pin connector, comprising: i) an electricallyconductive connector housing disposed on the circuit board, wherein theconnector housing is electrically connected to at least one electricalcircuit disposed on the circuit board; and ii) at least one electricallyconductive prong supported by the connector housing, the at least oneprong configured to contact and compress against a terminal pin; iii)wherein the terminal pin connector is configured to accept a hermeticalysealed feedthrough terminal pin extending into a casing of the AIMD.

In other exemplary embodiments, the at least one prong may comprise atleast two prongs, each prong configured to contact and compress againstthe terminal pin. Alternatively, the at least one prong may comprise aplurality of prongs, each prong of the plurality of prongs configured tocontact and compress against the terminal pin.

The connector housing may be electrically connected to the at least oneelectrical circuit with a solder, a braze, an electrically conductiveadhesive or a weld.

The terminal pin connector may be configured to allow multipleinsertions and retractions of the terminal pin without affectingreliability and enabling rework or pre-assembly testing.

The connector housing may comprise a housing sidewall defining a housingopening surrounded by a housing inner surface, wherein the at least oneprong comprises at least two prongs that extend from a base, the basesupported by the housing inner surface, wherein the at least two prongsare angled inwardly towards a central axis that extends longitudinallythrough a through-bore of the base, wherein the terminal pin isconfigured to be disposed through the through-bore of the base. Thehousing sidewall may comprise at least one planar surface contacting thecircuit board.

Referring generally to FIGS. 10-18, another exemplary embodiment of thepresent invention includes a hermetic feedthrough terminal pin connectorassembly configured for attachment to a casing of an active implantablemedical device (AIMD), the hermetic feedthrough terminal pin connectorassembly comprising: a) an electrically conductive ferrule configured tohermeticaly seal an opening of the casing of the AIMD; b) anelectrically nonconductive insulator hermetically sealing a ferruleopening; c) wherein the ferrule and the insulator are configured toprevent a leakage of a body fluid in a human implant application from abody fluid side of the casing to a device side of the casing; d) afeedthrough terminal pin hermetically sealed to and disposed through theinsulator, the feedthrough terminal pin extending outwardly beyond theinsulator on the body fluid side of the casing; e) a header configuredto be attached to the casing of the AIMD, the header comprising: i) aterminal pin connector, wherein the terminal pin connector comprises: 1)an electrically conductive connector housing; and 2) at least oneelectrically conductive elastically resilient termination structuresupported by the connector housing, the at least one elasticallyresilient termination structure contacting and compressed against thefeedthrough terminal pin extending outwardly beyond the insulator on thebody fluid side of the casing; and ii) a lead plug port configured toreceive a distal end of an implanted lead; and iii) a conductorelectrically connecting the lead plug port to the connector housing.

The connector housing and the at least one electrically conductiveelastically resilient termination structure of the terminal pinconnector may be made from materials which are biocompatible, non-toxicand biostable.

The terminal pin connector may be configured to be removable to allowmultiple insertions and retractions of the feedthrough terminal pinextending outwardly beyond the insulator on the body fluid side of thecasing of the AIMD without affecting reliability and enabling rework orpre-assembly testing.

Alternatively, the at least one elastically resilient terminationstructure contacting and compressed against the feedthrough terminal pinmay contact the terminal pin sidewall in a grip-tight engagementpreventing inadvertent removal of the feedthrough terminal pin from theterminal pin connector, while still allowing removability for rework orreplacement.

Another exemplary embodiment of the present invention includes aterminal pin connector header assembly for an active implantable medicaldevice (AIMD), the terminal pin connector header assembly comprising: a)a terminal pin connector, wherein the terminal pin connector comprises:I) an electrically conductive connector housing; and ii) at least oneelectrically conductive elastically resilient termination structuresupported by the connector housing, the at least one elasticallyresilient termination structure contacting and compressed against thefeedthrough terminal pin extending outwardly beyond the insulator on thebody fluid side of the casing; b) a lead plug port configured to receivea distal end of an implanted lead; and c) a conductor electricallyconnecting the lead plug port to the connector housing; e) wherein theconnector housing, the at least one electrically conductive elasticallyresilient termination structure and the conductor are disposed within aheader body.

In other exemplary embodiments, the connector housing and the at leastone electrically conductive elastically resilient termination structureof the terminal pin connector may be made from materials which arebiocompatible, non-toxic and biostable.

The terminal pin connector may be configured to allow multipleinsertions and retractions of the feedthrough terminal pin extendingoutwardly beyond the insulator on the body fluid side of the casing ofthe AIMD without affecting reliability and enabling rework orpre-assembly testing.

Alternatively, the at least one elastically resilient terminationstructure contacting and compressed against the feedthrough terminal pinmay contact the terminal pin sidewall in a grip-tight engagementpreventing inadvertent removal of the feedthrough terminal pin from theterminal pin connector.

Referring generally to FIGS. 27-28, another exemplary embodiment of thepresent invention includes a hermetic feedthrough terminal pin connectorassembly for an active implantable medical device (AIMD), the hermeticfeedthrough terminal pin connector assembly comprising: a) anelectrically conductive ferrule configured to hermetically seal anopening of a casing of the AIMD, the ferrule configured to prevent aleakage of a body fluid in a human implant application to an inside ofthe casing of the AIMD; b) an electrical insulator hermetically sealinga ferrule opening, the insulator configured to prevent the leakage ofthe body fluid in the human implant application to the inside of thecasing of the AIMD; c) a first EMI filter circuit board disposed on theinside of the casing of the AIMD, the first EMI filter circuit boarddisposed on, near or adjacent to the electrical insulator and/or theelectrically conductive ferrule; d) a feedthrough terminal pinhermetically sealed to and disposed through the insulator, thefeedthrough terminal pin extending outwardly beyond the insulator andoutwardly beyond the first EMI filter circuit board on the inside of thecasing of the AIMD; e) a chip filter capacitor disposed on the first EMIfilter circuit board, the chip filter capacitor having at least oneactive electrode plate disposed apart and parallel to at least oneground electrode plate within a capacitor dielectric, wherein the atleast one active electrode plate is electrically connected to thefeedthrough terminal pin and the at least one ground electrode plate iselectrically connected to the ferrule; f) a second circuit boarddisposed on the inside of the casing of the AIMD; and g) a terminal pinconnector, comprising: i) an electrically conductive connector housingdisposed on the second circuit board, wherein the connector housing iselectrically connected to at least one electrical circuit disposed onthe second circuit board; and ii) at least one electrically conductiveelastically resilient termination structure supported by the connectorhousing, the at least one elastically resilient termination structurecontacting and compressed against the feedthrough terminal pin extendingoutwardly beyond the insulator and the first EMI filter circuit board onthe inside of the casing of the AIMD.

In other exemplary embodiments, the at least one elastically resilienttermination structure may comprise at least one prong, the at least oneprong contacting and compressed against the feedthrough terminal pinextending outwardly beyond the insulator on the inside of the casing ofthe AIMD. In other exemplary embodiments, the at least one elasticallyresilient termination structure may comprise at least two prongs, eachprong contacting and compressed against the feedthrough terminal pinextending outwardly beyond the insulator on the inside of the casing ofthe AIMD. Alternatively, the at least one elastically resilienttermination structure may comprise a plurality of prongs, each prong ofthe plurality of prongs contacting and compressed against thefeedthrough terminal pin extending outwardly beyond the insulator on theinside of the casing of the AIMD.

In yet other exemplary embodiments, the at least one elasticallyresilient termination structure may include one or more additionalelastically resilient termination structures, the one or more additionalelastically resilient termination structures being all the sameconfiguration, each of a different configuration, or any configurationcombination between all the same and an different, each elasticallyresilient termination structure contacting and compressed against thefeedthrough terminal pin extending outwardly beyond the insulator on theinside of the casing of the AIMD.

The connector housing may be electrically connected to the at least oneelectrical circuit with a solder, a braze, an electrically conductiveadhesive or a weld.

The terminal pin connector may be configured to allow multipleinsertions and retractions of the feedthrough terminal pin extendingoutwardly beyond the insulator on the inside of the casing of the AIMDwithout affecting reliability and enabling rework or pre-assemblytesting.

The connector housing may comprise a housing sidewall defining a housingopening surrounded by a housing inner surface, wherein the at least oneelastically resilient termination structure comprises at least twoprongs that extend from a base, the base supported by the housing innersurface, wherein the at least two prongs are angled inwardly towards acentral axis that extends longitudinally through a through-bore of thebase, wherein the feedthrough terminal pin extending outwardly beyondthe insulator on the inside of the casing of the AIMD is disposedthrough the through-bore of the base. The housing sidewall may compriseat least one planar surface attached to and contacting the circuitboard.

A first ground terminal pin may be electrically connected to the ferruleand including a second terminal pin connector disposed on the secondcircuit board, wherein the first ground terminal pin is electricallyconnected to the second terminal pin connector. A second ground terminalpin may be electrically connected to the ferrule and including a thirdterminal pin connector disposed on the second circuit board, wherein thesecond ground terminal pin is electrically connected to the thirdterminal pin connector.

Referring generally to FIGS. 28A-D, another exemplary embodiment of thepresent invention includes a hermetic feedthrough terminal pin connectorassembly for an active implantable medical device (AIMD), the hermeticfeedthrough terminal pin connector assembly comprising: a) anelectrically conductive ferrule configured to hermetically seal anopening of a casing of the AIMD, the ferrule configured to prevent aleakage of a body fluid in a human implant application to an inside ofthe casing of the AIMD; b) an electrical insulator hermetically sealinga ferrule opening, the insulator configured to prevent the leakage ofthe body fluid in the human implant application to the inside of thecasing of the AIMD; c) a first EMI filter circuit board disposed on theinside of the casing of the AIMD, the first EMI filter circuit boarddisposed on, near or adjacent to the electrical insulator and/or theelectrically conductive ferrule; d) a first feedthrough terminal pinhermetically sealed to and disposed through the insulator, the firstfeedthrough terminal pin extending outwardly beyond the insulator andoutwardly beyond the first EMI filter circuit board on the inside of thecasing of the AIMD; e) a second feedthrough terminal pin hermeticallysealed to and disposed through the insulator, the second feedthroughterminal pin extending outwardly beyond the insulator and outwardlybeyond the first EMI filter circuit board on the inside of the casing ofthe AIMD; f) an X2Y attenuator filter capacitor disposed on the firstEMI filter circuit board, the X2Y attenuator filter capacitor having atleast one first and second active electrode plates disposed apart andparallel to at least one ground electrode plate within a capacitordielectric, wherein the at least one first active electrode plate iselectrically connected to the first feedthrough terminal pin, whereinthe at least one second active electrode plate is electrically connectedto the second feedthrough terminal pin, and wherein the at least oneground electrode plate is electrically connected to the ferrule; g) asecond circuit board disposed on the inside of the casing of the AIMD;h) a first terminal pin connector, comprising: i) an electricallyconductive first connector housing disposed on the second circuit board,wherein the first connector housing is electrically connected to atleast one first electrical circuit disposed on the second circuit board;and ii) at least one first electrically conductive elastically resilienttermination structure supported by the first connector housing, the atleast one first elastically resilient termination structure contactingand compressed against the first feedthrough terminal pin extendingoutwardly beyond the first EMI filter circuit board on the inside of thecasing of the AIMD; and i) a second terminal pin connector, comprising:i) an electrically conductive second connector housing disposed on thesecond circuit board, wherein the second connector housing iselectrically connected to at least one second electrical circuitdisposed on the second circuit board; and ii) at least one secondelectrically conductive elastically resilient termination structuresupported by the second connector housing, the at least one secondelastically resilient termination structure contacting and compressedagainst the second feedthrough terminal pin extending outwardly beyondthe first EMI filter circuit board on the inside of the casing of theAIMD.

Referring now generally to FIGS. 28E-H, another exemplary embodiment ofthe present invention includes a hermetic feedthrough terminal pinconnector assembly for an active implantable medical device (AIMD), thehermetic feedthrough terminal pin connector assembly comprising: a) anelectrically conductive ferrule configured to hermetically seal anopening of a casing of the AIMD, the ferrule configured to prevent aleakage of a body fluid in a human implant application to an inside ofthe casing of the AIMD; b) an electrical insulator hermetically sealinga ferrule opening, the insulator configured to prevent the leakage ofthe body fluid in the human implant application to the inside of thecasing of the AIMD; c) a first EMI filter circuit board disposed on theinside of the casing of the AIMD, the first EMI filter circuit boarddisposed on, near or adjacent to the electrical insulator and/or theelectrically conductive ferrule; d) a first feedthrough terminal pinhermetically sealed to and disposed through the insulator, the firstfeedthrough terminal pin extending outwardly beyond the insulator on theinside of the casing of the AIMD; e) a second terminal pin attached tothe first EMI filter circuit board, the second terminal pin extendingoutwardly beyond the first EMI filter circuit board on the inside of thecasing of the AIMD; f) a flat-thru filter capacitor disposed on thefirst EMI filter circuit board, the flat-thru filter capacitor having atleast one active electrode plate disposed apart and parallel to at leastone ground electrode plate within a capacitor dielectric, wherein the atleast one active electrode plate is electrically connected to the firstfeedthrough terminal pin at a first end of the at least one activeelectrode plate, wherein the at least one active electrode plate iselectrically connected to the second terminal pin at a second end of theat least one active electrode plate, and wherein the at least one groundelectrode plate is electrically connected to the ferrule; g) a secondcircuit board disposed on the inside of the casing of the AIMD; and h) aterminal pin connector, comprising: i) an electrically conductiveconnector housing disposed on the second circuit board, wherein theconnector housing is electrically connected to at least one electricalcircuit disposed on the second circuit board; and II) at least oneelectrically conductive elastically resilient termination structuresupported by the connector housing, the at least one elasticallyresilient termination structure contacting and compressed against thesecond terminal pin extending outwardly beyond the first EMI filtercircuit board on the inside of the casing of the AIMD.

Referring now generally to FIG. 19, another exemplary embodiment of thepresent invention includes a hermetic feedthrough terminal pin connectorassembly for an active implantable medical device (AIMD), the hermeticfeedthrough terminal pin connector assembly comprising: a) anelectrically conductive ferrule configured to hermetically seal anopening of a casing of the AIMD, the ferrule configured to prevent aleakage of a body fluid in a human implant application to an inside ofthe casing of the AIMD; b) an electrical insulator hermetically sealinga ferrule opening, the insulator configured to prevent the leakage ofthe body fluid in the human implant application to the inside of thecasing of the AIMD; c) a feedthrough terminal pin hermetically sealed toand disposed through the insulator, the feedthrough terminal pinextending outwardly beyond the insulator on the inside of the casing ofthe AIMD, wherein the feedthrough terminal pin extending outwardlybeyond the insulator on the inside of the casing of the AIMD includes anelastically resilient termination structure; and d) a circuit boarddisposed on the inside of the casing of the AIMD, the circuit boardcomprising a formed or stamped metallic eyelet electrically connected toa circuit trace; e) wherein the elastically resilient terminationstructure of the feedthrough terminal pin is at least partially disposedwithin the metallic eyelet electrically connecting the feedthroughterminal pin and the metallic eyelet.

Referring now generally to FIGS. 22, 23, 24, another exemplaryembodiment of the present invention includes a hermetic feedthroughterminal pin connector assembly for an active implantable medical device(AIMD), the hermetic feedthrough terminal pin connector assemblycomprising: a) an electrically conductive ferrule configured tohermetically seal an opening of a casing of the AIMD, the ferruleconfigured to prevent a leakage of a body fluid in a human implantapplication to an inside of the casing of the AIMD; b) an electricalinsulator hermetically sealing a ferrule opening, the insulatorconfigured to prevent the leakage of the body fluid in the human implantapplication to the inside of the casing of the AIMD; c) wherein theinsulator comprises a ceramic insulator body co-sintered with anelectrically conductive filled via, wherein the electrically conductivefilled via comprises a pure platinum or a ceramic reinforced metalcomposite; d) wherein the electrically conductive filled via comprises acounterbore formed therein; and e) an electrically conductive wirehaving at least one electrically conductive elastically resilienttermination structure supported at a distal end of the electricallyconductive wire; f) wherein the at least one electrically conductiveelastically resilient termination structure is contacting and compressedagainst an inside of the counterbore of the electrically conductivefilled via electrically connecting the electrically conductive wire tothe electrically conductive filled via.

Referring now generally to FIGS. 30-32, another exemplary embodiment ofthe present invention includes a hermetic feedthrough terminal pinconnector assembly for an active implantable medical device (AIMD), thehermetic feedthrough terminal pin connector assembly comprising: a) anelectrically conductive ferrule configured to hermetically seal anopening of a casing of the AIMD, the ferrule configured to prevent aleakage of a body fluid in a human implant application to an inside ofthe casing of the AIMD; b) an electrical insulator hermetically sealinga ferrule opening, the insulator configured to prevent the leakage ofthe body fluid in the human implant application to the inside of thecasing of the AIMD; c) a feedthrough terminal pin hermetically sealed toand disposed through the insulator, the feedthrough terminal pinextending outwardly beyond the insulator on the inside of the casing ofthe AIMD; d) a circuit board disposed on the inside of the casing of theAIMD; e) an electrically conductive terminal pin half pad disposed onthe circuit board and electrically connected to at least one circuittrace disposed on the circuit board; f) a terminal pin capture paddisposed opposite the electrically conductive terminal pin, wherein theterminal pin capture pad is attached to the circuit board with afastener; g) wherein at least a portion of the feedthrough terminal pinis disposed between and is compressed by the electrically conductiveterminal pin half pad and the terminal pin capture pad, wherein thefeedthrough terminal pin is electrically connected to the electricallyconductive terminal pin half pad.

Referring now generally to FIG. 33, another exemplary embodiment of thepresent invention includes a hermetic feedthrough terminal pin connectorassembly for an active implantable medical device (AIMD), the hermeticfeedthrough terminal pin connector assembly comprising: a) anelectrically conductive ferrule configured to hermetically seal anopening of a casing of the AIMD, the ferrule configured to prevent aleakage of a body fluid in a human implant application to an inside ofthe casing of the AIMD; b) an electrical insulator hermetically sealinga ferrule opening, the insulator configured to prevent the leakage ofthe body fluid in the human implant application to the inside of thecasing of the AIMD; c) a feedthrough terminal pin hermetically sealed toand disposed through the insulator, the feedthrough terminal pinextending outwardly beyond the insulator on the body fluid side of thecasing of the AIMD; d) a header block disposed on the outside of thecasing of the AIMD; e) an electrically conductive terminal pin half paddisposed on the header block and electrically connected to at least oneconductor disposed in the header block, the at least one conductorelectrically connected to at least one port disposed within the headerblock, wherein a distal electrode in contact with body tissue isconfigured to be plugged into the at least port; and f) a terminal pincapture pad disposed opposite the electrically conductive terminal pin,wherein the terminal pin capture pad is attached to the header blockwith a fastener; g) wherein at least a portion of the feedthroughterminal pin is disposed between and is compressed by the electricallyconductive terminal pin half pad and the terminal pin capture pad,wherein the feedthrough terminal pin is electrically connected to theelectrically conductive terminal pin half pad.

Referring now generally to FIGS. 34-34E, another exemplary embodiment ofthe present invention includes a hermetic feedthrough terminal pinconnector assembly for an active implantable medical device (AIMD), thehermetic feedthrough terminal pin connector assembly comprising: a) anelectrically conductive ferrule configured to hermetically seal anopening of a casing of the AIMD, the ferrule configured to prevent aleakage of a body fluid in a human implant application to an inside ofthe casing of the AIMD; b) an electrical insulator hermetically sealinga ferrule opening, the insulator configured to prevent the leakage ofthe body fluid in the human implant application to the inside of thecasing of the AIMD; c) a feedthrough terminal pin hermetically sealed toand disposed through the insulator, the feedthrough terminal pinextending outwardly beyond the insulator on the inside of the casing ofthe AIMD; d) a circuit board disposed on the inside of the casing of theAIMD; and e) an elastically resilient metallic clip disposed on thecircuit board and electrically connected to at least one circuit tracedisposed on the circuit board, the elastically resilient metallic cliphaving an opening configured for insertion of the feedthrough terminalpin; f) wherein at least a portion of the feedthrough terminal pinextending outwardly beyond the insulator on the inside of the casing isinserted through the opening in the elastically resilient metallic clipelectrically connecting the feedthrough terminal pin to the elasticallyresilient metallic clip.

Referring now generally to FIG. 20, another exemplary embodiment of thepresent invention includes a hermetic feedthrough terminal pin connectorassembly for an active implantable medical device (AIMD), the hermeticfeedthrough terminal pin connector assembly comprising: a) anelectrically conductive ferrule configured to hermetically seal anopening of a casing of the AIMD, the ferrule configured to prevent aleakage of a body fluid in a human implant application to an inside ofthe casing of the AIMD; b) an electrical insulator hermetically sealinga ferrule opening, the insulator configured to prevent the leakage ofthe body fluid in the human implant application to the inside of thecasing of the AIMD; c) a feedthrough terminal pin hermetically sealed toand disposed through the insulator, the feedthrough terminal pinextending outwardly beyond the insulator on the inside of the casing ofthe AIMD and supporting at least one electrically conductive elasticallyresilient termination structure; d) a circuit board disposed on theinside of the casing of the AIMD; and e) an electrically conductiveconnector housing disposed on the circuit board, wherein the connectorhousing is electrically connected to at least one electrical circuitdisposed on the circuit board; f) wherein the at least one elasticallyresilient termination structure is contacting and compressed against aninside surface of the electrically conductive connector housingelectrically connecting the connector housing and the feedthroughterminal pin.

Referring now generally to FIG. 24A, another exemplary embodiment of thepresent invention includes a hermetic feedthrough terminal pin connectorassembly for an active implantable medical device (AIMD), the hermeticfeedthrough terminal pin connector assembly comprising: a) anelectrically conductive ferrule configured to hermetically seal anopening of a casing of the AIMD, the ferrule configured to prevent aleakage of a body fluid in a human implant application to an inside ofthe casing of the AIMD; b) an electrical insulator hermetically sealinga ferrule opening, the insulator configured to prevent the leakage ofthe body fluid in the human implant application to the inside of thecasing of the AIMD; c) wherein the insulator comprises a ceramicinsulator body co-sintered with an electrically conductive filled via,wherein the electrically conductive filled via comprises a pure platinumor a ceramic reinforced metal composite; d) an electrically conductiveconnector housing disposed at least partially on the electricallyconductive filled via electrically connecting the connector housing tothe filled via; and e) at least one electrically conductive prong and atleast one electrically conductive wire, wherein either: i) the at leastone electrically conductive prong is supported by the conductive wire,wherein the at least one prong is contacting and compressed against aninside surface of the connector housing electrically connecting theconnector housing and the wire; or ii) the at least one electricallyconductive prong is supported by the connector housing, the at least oneprong contacting and compressed against the wire electrically connectingthe connector housing and the wire.

Referring now generally to FIGS. 8, 9, 9A, 9B, 14, another exemplaryembodiment of the present invention includes a hermetic feedthroughterminal pin connector assembly for an active implantable medical device(AIMD), the hermetic feedthrough terminal pin connector assemblycomprising: a) an electrically conductive ferrule configured tohermetically seal an opening of a casing of the AIMD, the ferruleconfigured to prevent a leakage of a body fluid in a human implantapplication to an inside of the casing of the AIMD; b) an electricalinsulator hermetically sealing a ferrule opening, the insulatorconfigured to prevent the leakage of the body fluid in the human implantapplication to the inside of the casing of the AIMD; c) a feedthroughterminal pin hermetically sealed to and disposed through the insulator,the feedthrough terminal pin extending outwardly beyond the insulator onthe inside of the casing of the AIMD; d) a circuit board disposed on theinside of the casing of the AIMD; and e) a terminal pin connector,comprising: i) an electrically conductive connector housing disposed onthe circuit board, wherein the connector housing is electricallyconnected to at least one electrical circuit disposed on the circuitboard, and wherein the connector housing comprises at least one flangeoutwardly extending outwardly beyond a side surface of the connectorhousing; and ii) at least one electrically conductive elasticallyresilient termination structure supported by the connector housing, theat least one elastically resilient termination structure contacting andcompressed against the feedthrough terminal pin extending outwardlybeyond the insulator on the inside of the casing of the AIMD; f) whereinthe side surface of the connector housing abuts the circuit board,wherein the at least one flange is disposed overhanging an edge of thecircuit board.

These and other objects and advantages of the present invention willbecome increasingly more apparent by a reading of the followingdescription in conjunction with the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a side perspective view of an embodiment of the AIMDfeedthrough connector assembly.

FIG. 2 illustrates an alternative embodiment of the AIMD feedthroughconnector assembly comprising a one-piece housing.

FIG. 3 shows a cross-sectional view of an embodiment of the AIMDfeedthrough connector assembly.

FIG. 3A shows a cross-sectional view of an alternative embodiment of theAIMD feedthrough connector assembly.

FIG. 3B shows a cross-sectional view of an alternative embodiment of theAIMD feedthrough connector.

FIG. 3C shows a cross-sectional view of an alternative embodiment of theAIMD feedthrough connector.

FIG. 3D shows a cross-sectional view of an alternative embodiment of theAIMD feedthrough connector assembly.

FIG. 4 shows a perspective view of an embodiment of the terminal pinconnector.

FIGS. 4A-4C illustrate embodiments of the clip of the connector housingof the terminal pin connector.

FIG. 5A shows a proximal end view of an embodiment of the terminal pinconnector.

FIG. 5B shows a cross-sectional view of the terminal pin connector ofFIG. 5A taken along lines 5B-5B.

FIG. 5C shows a distal end view of the terminal pin connector of FIG.5A.

FIG. 5D shows a cross-sectional view similar to FIG. 5B illustrating analternative embodiment of the terminal pin connector.

FIG. 5E shows a cross-sectional view similar to FIG. 5B illustrating analternative embodiment of the terminal pin connector.

FIG. 6A shows a proximal end view of an embodiment of the terminal pinconnector.

FIG. 6B shows a cross-sectional view of the terminal pin connector ofFIG. 6A taken along lines 6B-6B.

FIG. 6C shows a distal end view of the terminal pin connector of FIG.6A.

FIG. 7A illustrates an embodiment of the terminal pin connector attachedto an electrical connection pad of an AIMD active electronic circuitboard.

FIG. 7B illustrates an alternative embodiment of the terminal pinconnector attached to an electrical connection pad of an AIMD activeelectronic circuit board.

FIG. 7C illustrates an alternative embodiment of the connector assemblyattached to a via hole of an AIMD active electronic circuit board.

FIG. 8 shows an enlarged partial cross-sectional perspective view of anembodiment of an AIMD feedthrough connector assembly attached to theAIMD active electronic circuit.

FIG. 9 illustrates a perspective view of an embodiment of an AIMDfeedthrough connector assembly positioned within an AIMD casing half.

FIG. 9A illustrates a perspective view of an alternative embodiment ofthe terminal pin connector attachable to an AIMD hermetically sealedfeedthrough having a staggered terminal pin configuration.

FIG. 9B illustrates a perspective view of an alternative embodiment ofthe terminal pin connector attachable to an AIMD hermetically sealedfeedthrough having an orientation comprising aligned terminal pin pairsof different terminal pin lengths.

FIG. 10 illustrates an active implantable medical device connectable toa heart of a patient.

FIG. 11 shows a perspective view of an exemplary AIMD header block.

FIG. 12 illustrates a perspective first-side view of exemplary internalconductors, lead connectors and terminal pin connectors residing withinthe exemplary AIMD header block of FIG. 11.

FIG. 13 illustrates a perspective second-side view of the exemplaryinternal conductors, lead connectors and terminal pin connectors of FIG.12.

FIG. 14 illustrates the exemplary header block attachable to the AIMDpulse generator of FIG. 9, the AIMD header block comprising theexemplary components of FIGS. 11-13.

FIG. 14A shows a cross-sectional view of an alternative embodiment of afeedthrough capacitor connector assembly.

FIG. 15 shows a cross-sectional view of an alternative embodiment of afeedthrough capacitor connector assembly.

FIG. 16 shows a cross-sectional view of an alternative embodiment of afeedthrough capacitor connector assembly.

FIG. 17 shows a cross-sectional view of an alternative embodiment of afeedthrough capacitor connector assembly.

FIG. 18 is a perspective view of the clip of FIG. 17.

FIG. 19 shows a cross-sectional view of an alternative embodiment of afeedthrough capacitor connector assembly having terminal pins comprisinga compliant termination structure.

FIG. 19A illustrates an embodiment of a terminal pin having a complianttermination structure.

FIG. 19B illustrates an embodiment of a terminal pin with a complianttermination structure;

FIG. 19C illustrates an embodiment of a terminal pin with a complianttermination structure.

FIG. 19D illustrates an embodiment of a terminal pin with a complianttermination structure.

FIG. 20 shows a cross-sectional view of an alternative embodiment of aterminal pin connector.

FIG. 21 shows a cross-sectional view of an alternative embodiment of aterminal pin connector.

FIG. 22 shows a cross-sectional view of an alternative embodiment of anAIMD feedthrough connector assembly.

FIG. 23 shows a cross-sectional view of an alternative embodiment of anAIMD feedthrough connector assembly.

FIG. 24 shows a cross-sectional view of an alternative embodiment of anAIMD feedthrough connector assembly.

FIG. 24A shows a cross-sectional view of an alternative embodiment of anAIMD feedthrough connector assembly.

FIG. 25 shows a cross-sectional view of an alternative embodiment of aterminal pin connector assembly.

FIG. 26 shows a cross-sectional view of an alternative embodiment of aterminal pin connector.

FIG. 27 shows a cross-sectional view of an embodiment of the feedthroughconnector assembly taken along lines 27-27. Illustrated are terminal pinconnectors attached to terminal pins. It is noted that the terminal pinsare actually also attached to an AIMD active electronic circuit board(not shown) of the device side of an AIMD.

FIG. 27A illustrates an embodiment of an electrical connection to theground pin and the at least one ground electrode plate of an EMI filtercircuit board.

FIG. 27B illustrates an embodiment of an alternative electricalconnection to the ground pin and the at least one ground electrode plateof an EMI filter circuit board.

FIG. 27C illustrates an embodiment of an alternative electricalconnection to the ground pin and the at least one ground electrode plateof an EMI filter circuit board.

FIG. 27D illustrates an embodiment of an alternative electricalconnection to the ground pin and the at least one ground electrode plateof an EMI filter circuit board.

FIG. 27E illustrates an embodiment of an alternative electricalconnection to the ground pin and the at least one ground electrode plateof an EMI filter circuit board.

FIG. 27F illustrates an embodiment of an alternative electricalconnection to the ground pin and the at least one ground electrode plateof an EMI filter circuit board.

FIG. 27G illustrates an embodiment of an alternative electricalconnection to the ground pin and the at least one ground electrode plateof an EMI filter circuit board.

FIG. 27H illustrates an embodiment of an alternative electricalconnection to the ground pin and the at least one ground electrode plateof an EMI filter circuit board.

FIG. 28 is a top view taken along lines 28-28 of FIG. 27 showingmulti-layer ceramic capacitors (MLCCs) populated on an EMI fittercircuit board.

FIG. 28A is a perspective view of a prior art surface mounted capacitorknown as an X2Y attenuator.

FIG. 28B is a sectional view taken along lines 28B-28B of FIG. 28Ashowing the active and ground electrode plates of the X2Y attenuator.

FIG. 28C is similar to FIG. 28 except that illustrated are X2Yattenuators populating the EMI filter circuit board instead of MLCCs.

FIG. 28D is an electrical schematic for the configuration of FIG. 28C.

FIG. 28E is a perspective view of a prior art surface mounted capacitorknown as a flat-thru capacitor.

FIG. 28F is a sectional view taken along lines 28F-28F of FIG. 28Eshowing the active and ground electrode plates of the flat-thrucapacitor.

FIG. 28G is an electrical schematic for the configurations of FIGS. 28Eand 28H.

FIG. 28H is similar to FIG. 28C except that illustrated are flat-thrucapacitors populating the EMI filter circuit board instead of X2Yattenuators.

FIG. 28I shows a cross-sectional view of an alternative embodiment of afeedthrough connector assembly taken along lines 28I-28I. Illustratedare terminal pin connectors attached to terminal pins. It is noted thatthe terminal pins are actually also attached to an AIMD activeelectronic circuit board (not shown) of the device side of an AIMD.

FIG. 28J is a perspective view of a quad polar flat-thru capacitor.

FIG. 28K is a sectional view taken along lines 28K-28K of FIG. 28Jshowing the active and ground electrode plates of the quad polarflat-thru capacitor.

FIG. 29 shows a cross-sectional view of an alternative embodiment of afeedthrough connector assembly comprising various compliant terminationstructures. Illustrated are terminal pin connectors attached to terminalpins. It is noted that the terminal pins are actually also attached toan AIMD active electronic circuit board (not shown) of the device sideof an AIMD.

FIG. 30 shows a perspective view of an alternative embodiment of aterminal pin connector.

FIG. 30A is a perspective view of an alternative embodiment of an AIMDfeedthrough connector assembly attachable to an AIMD hermetically sealedfeedthrough having a staggered terminal pin configuration.

FIG. 31 is a cross-sectional view an alternative embodiment of an AIMDfeedthrough connector.

FIG. 32 is a cross-sectional view an alternative embodiment of an AIMDfeedthrough connector.

FIG. 33 is a perspective view of exemplary internal conductors, leadconnectors and terminal pin connectors residing of an AIMD header blockattachable to an AIMD hermetically sealed feedthrough.

FIG. 34 is perspective view of alternative embodiments of clips of aterminal pin connector attached to electrical connection pads of an AIMDactive electronic circuit board.

FIG. 34A is a sectional view of an alternative embodiment of a clipresiding in a circuit board via hole that is attachable to a terminalpin. The clip comprises a post that secures attachment to an AIMD activeelectronic circuit board.

FIG. 34B is a perspective view of an alternative embodiment of a clipattachable to a terminal pin.

FIG. 34C is a perspective view of an alternative embodiment of a clipattachable to a terminal pin.

FIG. 34D is a perspective view of an alternative embodiment of a clipattachable to a terminal pin.

FIG. 34E is a perspective view of an alternative embodiment of a clipattachable to a terminal pin.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Modern active implantable medical devices (AIMDs) 12, such asimplantable cardiac pacemakers, implantable cardioverter defibrillators,cardiac resynchronization devices, such as cardiac resynchronizationpacemakers and defibrillators, all have remote telemetry capability andprogramming capabilities. The AIMD active electronic circuit boards 106are extremely complex because they contain not only digital circuits,but also biological sensing circuits (analogue circuits). A modern AIMDmay have over 4,500 programmable functions and also may have extensivememory storage capability where doctors can retrieve waveforms after acardiac event. When an active electronic circuit board is built for suchAIMDs, it is placed on a large test console where computers extensivelycheck every function of the circuit board. The active electronic circuitboard becomes a defective circuit board if there is any single bit erroror logic error. Once the active electronic circuit board and the batteryare installed and the AIMD is hermetically sealed, the AIMD thenundergoes final testing.

If the AIMD active electronic circuit board is found to be defective atfinal testing, it is too late to replace the defective circuit board. Asused herein, active circuit boards are defined as AIMD active electroniccircuit boards which require a power source and have one or moreelectronic components, including microchips and the like. The termactive as used herein also apply to active terminal pins or activeco-sintered conductive vies, which constitute conductive pathways thatpass through the hermetic terminal insulator to circuits that are activecircuits. In this context, active is defined as a terminal pin orcircuit or even implanted therapy delivery leadwire which conductstherapeutic pacing pulses and/or senses biological signals. In general,active circuits require a power source such as a primary or secondarybattery. This is in contrast to ground terminal pins or ground circuittraces, which are generally at the potential of the AIMD casing 32.

Circuit boards come in a multitude of sizes, shapes and materials. Theymay be single layer or multi-layer with surface circuit traces, embeddedcircuit traces or both, and surface ground electrode plates, embeddedground electrode plates or both, including through-hole, surface mount,and/or optional embedded components. Typical circuit board materialsinclude fiberglass, alumina ceramic, FR-4 (or FR4) and the like. Circuitboards are often called printed circuit boards (PCBs), which refer tohow circuit traces are laid out. Circuit boards typically have a numberof active and ground conductive paths (sometimes called conductivepathways).

Referring now to the Provisional Patent Application No. 61/492,828 filedon Jun. 3, 2011, the following paragraphs are excerpts taken from the'828 Provisional. Wording shown in quotation marks are quoted directly.

The '828 Provisional states: “How was the problem addressed beforeinvention: 1) Use of expensive, but solderable biostable feedthroughwire material, such as platinum or palladium; 2) Use of additionalcoatings on feedthrough wires using expensive processes, such asselective physical vapor deposition or selective electro (orelectroless) plating to make surface to wire solderable; 3) Additionalcoatings on wire materials that have marginal or poor solderability,such as nickel or platinum-iridium alloys, by using a hot solder dippingoperation after feedthroughs have been assembled; 4) Use of laserwelding feedthrough wires to printed circuit board mounted contacts orcontact clips; 5) Use of resistance welding feedthrough wires to printedcircuit board mounted contacts or contact clips.” The foregoing listsissues with how prior art connections between unfiltered feedthroughsand/or filtered feedthrough assemblies and an AIMD active electroniccircuit board.

The '828 Provisional also states: “What are short-comings of previousways to solve the problem: 1) Feedthrough wires made from solderablematerial that are also biostable and biocompatible are, in comparison,very expensive; 2) Feedthrough wires coated with physical vapordeposition and/or electro (and electroless) plating are, in comparison,very expensive; 3) Feedthrough wires connected to printed circuit boardsusing laser welding or resistance welding is, in comparison, veryexpensive; 4) Feedthrough wires connected by all of the above processesare not disconnected without destructive techniques (e.g. once welded orsoldered, the feedthrough and/or printed circuit board are mated for theproduct's life without damage to either both the feedthrough and/orprinted circuit board.)” As such, the '828 provisional discloses thatonce the AIMD active electronic circuit board is connected, it ispermanently attached and cannot realistically be removed. In the case ofa defective circuit board, this means the entire AIMD must be scrappedor at least most of the AIMD pulse generator, including a casing half, abattery, among possibly other costly components, such as high energystorage capacitors if the AIMD is an implantable cardioverterdefibrillator (ICD).

As previously disclosed, a modern AIMD circuit board is complex, havingover 4,500 programmable functions and can also be capable of storingbiological wave forms, for example, but not limited to, cardiac waveforms for a pacemaker or an ICD. The prior art methods of connectingfeedthrough wires to the circuit board involve processes, such asthermal sonic bonding, wire bonding, welding, soldering or the like,typically apply heat and pressure to the components being connected.Hence, even though AIMD active electronic circuit boards are pretestedthrough an automated test system, which is costly in and of itself, suchconnection methods using thermal energy and mechanical force, can and dodamage AIMD active electronic and other circuit boards. The embodimentsof the present application resolves these issues, as the novelconnectors of the present application allow equally reliable connectionof AIMD components without introducing damaging amounts of thermalenergy or mechanical force, while enabling insertion and retraction ofcomponents so that defective components can be removed for replacementor rework (replacement and rework of defective components being morecost-effective compared to scrapping costly assembles and/or fullyassembled products).

Continuing on, the '828 Provisional states: “By modifying existingcommercially available connectors to meet wire pitch requirements, amechanical and electrical connection can be made to feedthrough wires.This connector could be populated on the circuit board at the same time,all other components are populated and reflowed.” As used therein, theword “populated” is a very common term of art applied to circuit boardassembly and implies that robots can be used to pick and place all ofthese components, including the terminal pin connectors 16 disclosedherein (which would also be automatically populated). Typically, oncethe board is populated, then all the electrical connections, such as BGAor solder joints, are made at the same time. After the board ispopulated and cleaned, it goes through extensive electrical andfunctional testing. Typically, an automated test console is used tocheck all of its programmable and non-programmable functions. It is veryimportant that after this testing, the board be handled very gently andnot be exposed to undo mechanical forces or thermal shocks, such assoldering or welding. This is because such mechanical forces or thermalshocks result in residual stresses and strains that can induce immediateor latent defects in the circuit board. Latent defects are a veryworrisome risk as these types of defects are often not discovered untila device has been in the field (implanted in the human) for months oryears. The connectors taught herein allow the AIMD active electroniccircuit board 106 insertion and retraction (removability) withoutimparting undo mechanical or thermal stresses.

The '828 Provisional states: “This connector could also be attachedthrough feedthrough wires at the end of the feedthrough assemblyprocess. This connector allows multiple insertions/retractions withoutaffecting reliability, thus enabling rework or pre-assembly testing. Theconnector could be mounted in one unique-body insulating structure orkept as individual components.” It is understood that the feedthroughwires mentioned are the terminal pins 18 taught herein. What thisparagraph is saying is that the connector disclosed allows multipleinsertions/retractions without affecting reliability. This means that areworked or a new circuit board could easily be plugged in to replace adefective circuit board. In general, removal of defective circuit boardsand plugging in a replacement or reworked circuit board would bepreferred but is not possible without the embodiments taught herein.Additionally, the connector embodiments disclosed herein also apply toan AIMD header block, such that a defective AIMD header block could beremoved and reworked or replaced.

Hence, as the '828 provisional teaches, “by modifying existingcommercially available connectors” such that the commercially availableconnectors can be integrated with AIMD circuit boards and AIMD headerblocks, wherein the connectors integrated with AIMD circuit boards andAIMD header blocks can be removably connected not only resolves theissues associated with the present AIMD circuit board and AIMD headerblocks, but also forms an equally reliable connection while alsominimizing production scrap levels thereby lowering manufacturingfinancial losses. Exemplary embodiments of novel modifications ofcommercially available AIMD connectors available from, for example, butnot limited to, Mill-Max®, Samtec, Amphenol, ITT, Airborn, SmithsInterconnect, ODU GmbH & Co. KG, Positronic, Molex, 3M, InterplexIndustries, preci-dip, TE Connectivity, NEPCON, KEL Corporation, amongothers, in addition to various custom novel connector embodiments, aretaught and disclosed herein.

The present patent application thus relates to removable connectorassemblies that allow rework and/or replacement of defective circuitboards. With the present invention, extensive testing of any circuitboard of an AIMD can be completed before welding the final can halfthereby hermetically sealing the AIMD. The term “can” is defined hereinas a case, a casing or a housing of an AIMD. In the event that adefective circuit board is discovered, the present invention makes iteasy to remove the defective circuit board from its AIMD subassembly andthen plug in a new functional replacement circuit board. By doing this,one saves a number of expensive components, including the AIMD casing(can half), the AIMD hermetically sealed feedthrough, if present, theEMI filter of the AIMD hermetically sealed feedthrough, the AIMD powersource(s), for example, a battery, or, in the case of a defibrillator,the high energy storage capacitors, other potentially costly mountingcomponents, other hardwired additional circuit boards, or potentiallycostly high-voltage switches.

As present-day feedthrough assemblies for modern AIMDs may comprisesintered conductors, such as, but not limited to, a co-sinteredconductive paste-filled via, instead of conventional terminal pins, suchsintered conductors present additional challenges for creating robustand reliable circuit board connections. For example, conventional AIMDfeedthroughs typically comprise one or more terminal pins 18, whichgenerally have some length extending outwardly beyond either the bodyfluid side insulator surface 36, the device side insulator surface 38,or both the body fluid and device side insulator surfaces 36, 38 of theAIMD hermeticaly sealed feedthrough 14. Either one or both ends of theterminal pin(s) 18 is/are electrically directly connectable to one of acircuit board within the active implantable medical device 14, to one ormore components, a subassembly, an assembly, or combinations thereofoutside of the active implantable medical device 14, or in variouscombinations of both the inside and the outside of the activeimplantable medical device 14. As used herein, inside the activeimplantable medical device is defined herein as the device side of theactive implantable medical device, and outside the active implantablemedical device is defined herein as the body fluid side of the activeimplantable medical device. In the device side case, the terminal pindistal end 62 is typically electrically connected to an activeelectrical circuit residing within the AIMD casing. In the body fluidside case, the terminal pin distal end is typically electricallyconnected to a structure configured for electrical stimulation, forexample, an AIMD header block to which implantable leads with electrodesconnect. In either case, electrical connection is typically made by asoldering or a welding attachment process. While this connection isreadily achievable in the prior art, these processes are often complexand time consuming, lowering throughput efficiencies, and sometimes evenrequiring manual operations. These processes also can be difficult andcan pose risk of damage to the parts being connected, which includes anAIMD active electronic circuit board 106 and/or an EMI filter circuitboard 106′. Furthermore, in the case of soldering, depending on thesolder process, flux residues or solder balls may occur, adding furthermanufacturing complications. As a result, such soldering and weldingprocesses can additionally involve complex and time consuming cleaning,testing and inspection protocols. Of particular significance, however,is that these processes may be prohibitively costly when pre-assembledparts are found to be out of specification during inspection or havefailed testing and/or evaluation requirements and cannot be reworked orreplaced. Moreover, the cost of failure can be particularly substantial,even excessive, when a device is at an almost completed stage ofmanufacturing and is either not reworkable or if reworkability isunreasonable. Accordingly, the novel removable terminal pin connectors16 of the present application provide cost-effective electricalconnection without sacrificing AIMD quality, reliability andperformance, and provides connector embodiments that resolve theseconcerns. The removable terminal pin connectors 16 additionally provideoptions for insertable and retractable AIMD header blocks. As such, thepresent invention teaches the use of various removable terminal pinconnectors for use on the body fluid, the device side, or both the bodyfluid and the device sides of AIMDs.

The removable terminal pin connectors as taught herein, include somecommercially available non-AIMD connectors and how the commerciallyavailable parts can be integrated with an AIMD such that removabilityfrom the AIMD permits replacement or rework of a defective component,subassembly, assembly, portion or part, thereby reducing costs ofquality associated with product failures. Of particular significance isthat such commercially available electrical connectors as taught hereinwere not contemplated or intended for use in AIMDs by those skilled inthe art. Moreover, removable terminal pin connectors are still not beingused today in active implantable medical devices. This is because thoseskilled in the art failed to teach, suggest or appreciate a way to testAIMD circuit boards or header blocks after being fully or partiallyinstalled in or on an AIMD. Furthermore, those skilled in the art wouldnot even have been motivated to teach, suggest or appreciate replacementor rework of AIMD circuit boards or header blocks because, onceinstalled using processes such as soldering and welding, removabilitywas considered impossible or impractical. Hence, even if those skilledin the art could test for defective AIMD circuit boards or headerblocks, then the defective AIMD circuit boards or header blocks, and theassociated other components of the assembly at the time the defect wasidentified, were considered irrecoverable internal failure costs due toproduct performance failure.

The present application teaches that a defective component, subassembly,assembly, portion or part of an AIMD can indeed be either replaced orreworked. For example, in the case of circuit boards, the presentapplication teaches that a defective circuit board can either be easilyremoved and replaced with a new functional circuit board or that adefective circuit board could be removed and then reworked such that thedefective circuit board functionality is acceptably restored. Similarly,this reasoning can be applied to AIMD header blocks. Moreover, theability to install and test an AIMD circuit board or a header blockafter installation such that the defective component, subassembly,assembly, portion or part of the AIMD can be replaced or reworkedprovides cost and time saving advantages that were previously consideredirrecoverable internal failure costs.

The use of connectors that facilitate insertion and retraction of eitherAIMD circuit boards and/or AIMD header blocks was particularlycounter-intuitive since such connectors take up both space and addweight to the overall AIMD. All the thinking by those skilled in the artin the AIMD industry is directly contrary to improving, adding orinnovating ‘anything’ that would add any size or weight to activeimplantable medical devices. In fact, research related to modern AIMDsfocused heavily on miniaturization of AIMDs. As such, it has been andstill is particularly important for all active implantable medicaldevices that they be very small and very thin for patient comfort andpatient safety. Using an implantable cardiac pacemaker as an example, itis typically inserted in the pectoral area of the human chest eithersubmuscular (sub-pectoral) or subcutaneous (under the skin). Early modelpacemakers that were thicker caused a very unpleasant bulge under thepatient's skin, which many patients found to be uncomfortable andirritating. Accordingly, adding additional components, such as AIMDcircuit board and/or header block connectors, is contrary to the entireindustry trend to those of skill in the art who were ideating andinnovating to make things smaller and smaller and lighter and lighter.It is only when the present inventors understood that circuit boards forAIMDs had become so complex and the other associated components socostly that the ability to replace a defective circuit board overcamethe disadvantages of adding additional components, that potentiallymight add some size and/or weight to an AIMD. During the development ofthe removable AIMD circuit board invention, the inventors alsounderstood the need for and the ability to rework an AIMD header blockon the body fluid side of AIMDs, thereby conceiving the removable AIMDheader block.

The inventors performed due diligence regarding a wide variety ofconnector art, including various types of circuit board connectors andconnectors for potential use with other AIMD components like AIMD headerblocks. None of the prior art discovered by the inventors were designedor in any way intended or contemplated for use in any active implantablemedical device. More specifically, no AIMD discovery forremovable/replaceable AIMD circuit boards or header blocks even emergedduring the due diligence process. Additionally, discovered AIMD circuitboard or header block related patents do not even address the uniquerequirements for or even consider the concept of a replaceable AIMDcircuit board or a header block for an active implantable medicaldevice. Such discovered patents include U.S. Pat. Nos. 3,621,445;5,893,779; 6,183,301; 7,249,981; 8,900,008; and 9,806,443, the contentsof all of which are fully incorporated herein by these references.

Accordingly, to date, the inventors are not aware of any teaching ofconnectors being used in active implantable medical devices 12 in orderto permit removability of an AIMD circuit board and/or a header block.Additionally, none of the prior art discovered taught structures and/orconfigurations for a terminal pin(s) 18 and/or the via configurations ofa co-sintered paste-filled via(s) 146 that include a hermetically sealedferrule 26, an insulator 28, and either a feedthrough capacitor 24, 24′,24″ or an EMI filter circuit board 106′ that could take advantage of theterminal pin connectors 16 of the present invention such that at leastone of an AIMD active electronic circuit board 106, an EMI filtercircuit board 106′, an AIMD header block 118, or combinations thereofare removable. Furthermore, none of the prior art taught the use ofterminal pin connectors 16 for use on the body fluid side of an AIMD,which permit removability and are biocompatible, non-toxic andbiostable. For at least these reasons, the embodiments of the presentapplication are indeed novel and are being disclosed for the first timeby the teaching of this and the applications of the priority chainherein.

The removable electrical terminal pin connector 16 of the presentapplication Is specifically for use in AIMDs, the removable electricalterminal pin connector 16 providing electrical connection between one ormore components of the AIMD and one or more feedthrough conductivepathways, wherein the one or more feedthrough conductive pathways areselected from the group consisting of a terminal pin, a pin, a leadwire,a lead wire, a two-part pin, a lead conductor, a sintered paste-filledvia, a co-sintered via, a co-sintered via with one or more metallicinserts, or combinations thereof, and wherein the component of the AIMDcomprises one of a circuit, a circuit board, an electrical component, aheader, a header block, or combinations thereof. An AIMD component beingconnected to a feedthrough conductive pathway may reside on either adevice side or on a body fluid side of the AIMD. The term “component” asused herein is defined as either an individual part or element, or, oneor more parts or elements that make up a subassembly or an assembly(like an AIMD active circuit electronic board or a header block) of anAIMD.

The removable terminal pin connectors 16 of the present application donot substantially increase resistance and/or impedance at the point ofconnection and do not compromise the intended electromechanicalperformance of the AIMD, yet such terminal pin connectors 16 permitinsertion and retraction of an AIMD component from the one or morehermetically sealed feedthrough conductive pathways (such as terminalpin 18 or co-sintered conductive paste-filled via 146) without damage toeither the component or the one or more feedthrough conductive pathwaysbeing connected. Further, the insertion and retraction capability of theterminal pin connectors 16 disclosed herein provides reworkabilityand/or replacement of any portion of the AIMD that has been determinedto be out of specification, or that has failed quality, reliability,testing or evaluation requirements. In summary, the AIMD component beingconnected to the one or more hermetically sealed feedthrough conductivepathways may comprise one of an assembly, a subassembly, a structure, abody, an element, a part, a circuit, a circuit board, a header, a headerblock or combinations thereof. Hermetically sealed feedthroughconductive pathways may comprise terminal pins, leadwires, lead wires,two-part pins, co-sintered insulator vias, co-sintered metallic inserts,co-sintered connector components and combinations thereof.

The removable connectors of the present application provide someembodiments comprising compliant designs. The term “compliant” isdefined herein as an elastically resilient structure (i.e., a structurethat resists a distorting influence and returns to its original formwhen that influence or force is removed, meaning its elastic limit oryield point was not reached) that may comprise a prong, a tine, afinger, an elongated member or a spring-like structure and that alsoprovides a mechanical and an electrical interface between a component(such as an AIMD active electronic circuit board, an EMI filter circuitboard or an AIMD header block) and a hermetically sealed feedthroughconductive pathway. The compliant design further permits insertion andretraction of an AIMD component from a hermetically sealed feedthroughconductive pathway. The compliant design may either be a separateindependent structure, a part of a connector housing, or an integralpart of the hermetically sealed feedthrough conductive pathway.Additionally, a terminal pin connector 16 may comprise either aone-piece construction, a two-piece construction, or a multi-piececonstruction. In some embodiments described herein, compliantterminations may comprise one or more prongs. As used herein, prong isdefined as a projecting part, a tapering projection, or an elongateextension from a base structure. The term “prong” is used within thisapplication interchangeably with the term “tine” and are synonymous. Insome embodiments described herein, compliant designs may comprise abi-spring design, known in the industry as “eye of the needle”.

The following detailed description and figures teach various embodimentsof the novel terminal pin connectors 16 for an AIMD feedthroughconnector assembly 10 of the present invention. The AIMD feedthroughconnector assembly 10 is useful with medical devices, such as an activeimplantable medical device (AIMD) 12 as shown in FIG. 9 which can be apacemaker, cardiac defibrillator, cardioverter defibrillator, cochlearimplant, neurostimulator, drug pump, deep brain stimulator, hearingassist device, incontinence device, obesity treatment device,Parkinson's disease therapy device, bone growth stimulator, spinal cordstimulator and other such devices, which are either implanted,temporarily implanted, or otherwise external the human body.

As shown in FIG. 1, the AIMD feedthrough connector assembly 10 comprisesan AIMD hermetically sealed feedthrough 14 and a terminal pin connector16. The AIMD hermetically sealed feedthrough 14 of the AIMD feedthroughconnector assembly 10 includes terminal pins 18 that provide forconducting electrical signals to and from body tissue, such as apatient's heart, while hermetically sealing the interior (device side)of the AIMD 12 (not shown) against ingress of patient body fluids thatcould otherwise disrupt AIMD operation or cause AIMD malfunction.

FIG. 2 is very similar to FIG. 1, except that the AIMD feedthroughconnector assembly 10 now includes an internally grounded feedthroughcapacitor 24′, as illustrated. Internally grounded feedthroughs aretaught by U.S. Pat. No. 5,905,627, the contents of which are fullyincorporated herein by this reference. As illustrated, the internallygrounded feedthrough capacitor 24′ is disposed on the device side of theAIMD feedthrough connector assembly 10. In accordance with the presentinvention, illustrated in the embedment of FIG. 2 are terminal pinconnectors 16 all contained within a common housing body 94. The commonhousing body 94 may comprises a metallic structure, a ceramic structure,or a structure comprising a ceramic and a metal. The common housing body94 may further be an insulated housing body comprising a ceramicstructure, or a ceramic structure with metal structures optionallypositioned in, on or about the ceramic structure. In the case where thecommon housing body 94 is metallic, it is contemplated that aninsulating material would be contained inside the common housing body94, the insulating material positioned to thereby electrically insulateeach of the terminal pins 18 one from the other. The individual terminalpin connectors 16 are not shown as they are embedded in the commonhousing body 94. It is contemplated that the common housing body 94 maycomprise terminal pin connectors 16 having similar or the same shape andconfiguration as the terminal pin connectors 16 previously described inFIG. 1 or may comprise any of the connector structures disclosed herein.The common housing body 94 may further comprise any combination ofconnector structures disclosed, including terminal pin connector 16. Asused herein, the term “common housing body” is defined as one connectorhousing in which two or more connector structures or terminal pinconnectors reside.

Referring once again to FIG. 2, one will see the internally groundedfeedthrough capacitor 24′ is shown vertically aligned with the ferrule26 structure. The illustrated internally grounded feedthrough capacitor24′ is exemplary only, including how the internally grounded feedthroughcapacitor may be attached to a ferrule 26. There are various waysfeedthrough capacitors may be attached. For example, attachment ofexternally grounded feedthrough capacitors 24 to AIMD hermeticallysealed feedthroughs 14 is well known in the prior art and includes, U.S.Pat. No. 5,333,095, (otherwise known as the Surface Mount patent); andU.S. Pat. Nos. 5,978,204; 5,905,627 (Internal Ground patents, whichwould require the addition of at least one internally grounded terminalpin 18 gnd that would be connected to the ferrule 26), the contents ofwhich are fully incorporated herein by these references. Following areadditional patents that disclose externally grounded feedthroughcapacitors 24: U.S. Pat. Nos. 6,643,903; 6,765,779; 7,035,076;7,917,219; 8,179,658; 8,422,195; 8,433,410; 8,468,664; 8,543,209;8,577,453; 8,659,870; 8,653,384; 8,855,785; 8,868,189; 9,014,808;9,064,640; 9,108,066; 9,352,150; 9,427,596; 9,483,329; 9,757,558;9,764,129; re-issue 46,699; re-issue 46,837; 9,895,534; 9,889,306;9,931,514; 9,993,650; 10,080,889; 10,092,749; 10,099,051; 10,124,164;10,249,415; 10,272,252; 10,272,253 and 10,350,421, the contents of whichare also fully incorporated herein by these references.

FIG. 3 illustrates a cross-sectional view of an alternative embodimentof an externally grounded feedthrough capacitor 24 of the feedthroughcapacitor connector assembly 20 disclosed herein. Externally groundedfeedthrough capacitors 24 are also known in the industry asconventionally grounded feedthrough capacitors. Internally groundedfeedthrough capacitors 24′ and hybrid feedthrough capacitors 24″ canalternatively be used in feedthrough capacitor connector assemblies 20.Hybrid feedthrough capacitors 24″ comprise both an external ground andan internal ground. As used herein, a filtered feedthrough assembly 22comprises an AIMD hermetically sealed feedthrough 14 and a filtercapacitor 24 (24′, 24″ not shown), the filter capacitor comprising oneof an externally grounded feedthrough capacitor 24, an internallygrounded feedthrough capacitor 24′ or a hybrid feedthrough capacitor24″, wherein the filter capacitor is mounted or attached to the AIMDhermetically sealed feedthrough 14. Also, as used herein, a feedthroughcapacitor connector assembly 20 comprises a filtered feedthroughassembly 22 and terminal pin connectors 16. In summary, it iscontemplated that the feedthrough capacitor could be an externallygrounded feedthrough capacitor 24, an internally grounded feedthroughcapacitor 24′ (see U.S. Pat. No. 5,905,627 incorporated herein fully byreference), or a hybrid feedthrough capacitor 24″ (see U.S. Pat. No.6,765,780 incorporated herein fully by reference), which includes boththe features of the internally grounded feedthrough capacitor 24′ andthe externally grounded feedthrough capacitor 24.

Referring once again to FIG. 3, shown is a cross sectional view offeedthrough capacitor connector assembly 20 comprising an externallygrounded feedthrough capacitor 24. As previously disclosed, feedthroughcapacitor connector assemblies 20 may incorporate both an externallygrounded feedthrough capacitor 24 as shown, or an internally groundedfeedthrough capacitor 24′ (not shown), or a hybrid feedthrough capacitor24″ (also not shown), the hybrid feedthrough capacitor 24′ comprisingboth an external ground and an internal ground. As illustrated, theexternal ground of FIG. 3 comprises an external ground electrical pathcomprising an outer metallization layer 60 residing on the externallygrounded feedthrough capacitor 24, an electrical connection material 54,a braze material 46 a residing between the ferrule 26 and the insulator28 of the AIMD hermetically sealed feedthrough 14, and the ferrule 26.The terms “hermetic”, “hermeticaly sealed” and “hermetic seal” refer toan enclosure, a feedthrough, and/or a seal comprising a leak rate nogreater than 1×10−7 std cc He/sec. It is understood, that insulator 28could comprise one of a ceramic, a glass, a glass-ceramic, orcombinations thereof. As previously disclosed, the feedthrough capacitorconnector assembly 20 may alternatively comprise an internal ground astaught by U.S. Pat. No. 6,765,780 incorporated herein fully byreference. One is referred to FIG. 42 of the '780 patent as an exemplaryinternal ground electrical path. The feedthrough capacitor connectorassembly 20 of FIG. 3 may also optionally incorporate the teachings of anumber of other patents, including U.S. Pat. Nos. 4,424,551; 5,333,095;6,643,903; and 6,765,779, the contents all of which are fullyincorporated herein by these references.

As illustrated in FIG. 3 the feedthrough capacitor connector assembly 20comprises a filtered feedthrough assembly 22 comprising an externallygrounded feedthrough capacitor 24 that is attached to the AIMDhermetically sealed feedthrough 14. Like the AIMD feedthrough connectorassembly 10 of FIG. 1, the feedthrough capacitor connector assembly 20of FIG. 3 comprises terminal pin connectors 16. In this embodiment, theexternally grounded feedthrough capacitor 24 is attached to the bodyfluid side of the AIMD hermetically sealed feedthrough 14 such thatundesirable electromagnetic interference (EMI) signals and noisetransmission into the interior (device side) of the medical device aresuppressed or decoupled as taught by U.S. Pat. No. 7,917,219, thecontents of which are fully incorporated herein by this reference. Moreparticularly, the AIMD hermetically sealed feedthrough 14 of the AIMDfeedthrough connector assembly 10 of FIG. 1 and the filtered feedthroughassembly 22 of FIG. 3, comprises a an electrically conductive ferrule 26comprising a ferrule opening extending to a ferrule body fluid sideopposite a ferrule device side and an insulator 28 residing in theferrule opening where a gold braze 46 a hermetically seals the insulator28 to the ferrule 26. Suitable electrically conductive materials for theferrule 26 include titanium, tantalum, niobium, stainless steel orcombinations of alloys thereof, titanium being preferred. The ferrule 26may be of any geometry; non-limiting examples being curved, round, oval,rectangular, square and oblong. A ferrule 26 may comprise a flange 30,the flange extending from and surrounding the ferrule 26 to facilitateattachment of the feedthrough 14 to an AIMD casing 32 (not shown) of theactive implantable medical device 12 (also not shown). The flange 30 ofthe ferrule 26 illustrated in FIG. 3 is a capture flange, also known asan H-flange, which captures the AIMD casing halves 112, 114 (not shown)for subsequent joining. While FIG. 3 illustrates an H-flange, flange 30may alternatively be an L-flange, an F-flange, an indent flange or abarrel flange. The method of attachment of the ferrule 26 comprisingflange 30 to the AIMD casing 32 may be by laser welding, brazing,soldering or other suitable joining methods.

The insulator 28 is of an insulative material such as a ceramic, glassor glass-ceramic, or combinations thereof. Suitable ceramic insulatingmaterials may be selected from the group consisting of alumina,zirconia, zirconia toughened alumina, aluminum nitride, boron nitride,silicon carbide, or combinations thereof. Suitable biostable glassinsulating materials may be selected from the group consisting of SiO₂,Al₂O₃, MgO, CaO, Na₂O, B₂O₃, SrO, or combinations thereof, and whereinthe SiO₂ content of the biostable glass is at least about 60%. Suitablebiostable glass-ceramic insulating materials may be selected from thegroup consisting of alumina, zirconia, zirconia toughened alumina,aluminum nitride, boron nitride, silicon carbide, SiO₂, Al₂O₃, MgO, CaO,Na₂O, B₂O₃, SrO, or combinations thereof. In some embodiments, theinsulating material is alumina, which is high purity aluminum oxide, andcomprises an insulator sidewall 34 extending to a body fluid sideinsulator surface 36 (which may be a first or upper side) and a deviceside insulator surface 38 (which may be a second or lower side). Theinsulator 28 is also provided with insulator bores 40 that receive theterminal pins 18 passing therethrough. The insulator 28 comprises aninsulator sidewall 34 and one or more insulator bores 40, the one ormore insulator bores comprising an insulator bore sidewall 44. Theinsulator sidewall 34 and the insulator bore sidewalls 44 each comprisea layer of metal, defined herein as a metallization layer 42. It isunderstood that the metallization layer 42 may comprise one or morelayers of metal. The metallization layers 42 on the insulator sidewall34 and the insulator bore sidewalls 44 of the insulator 28 are appliedso that during a brazing process, a first braze material 46 a may form ahermetic seal between the ferrule 26 and the insulator sidewall 34 ofthe insulator 28, and a second braze material 46 b may form a hermeticseal between the terminal pins 18 and the insulator bore sidewall 44 ofthe one or more insulator bores 40 of the insulator 28. Hermetic sealingof the terminal pins 18 to the insulator 28 and the insulator 28 to theferrule 26 may be done in a single brazing process, wherein the brazematerial is of the same composition. Alternatively, the brazing processmay a step-brazing process, wherein two different braze materials areused for each hermetic seal, wherein each braze material has a differentmelting temperature. In one embodiment, the braze materials 46 a and 46b may be selected from the group consisting of gold, silver, goldalloys, silver alloys, or combinations thereof. Referring again to themetallization layer 42, is understood that the metallization layers 42are intended to facilitate wetting of the braze materials 46 a, 46 b tothe insulator sidewall 34 and the insulator bore sidewalls 44respectively such that contact and metallurgical bonding of theinsulator 28 with the ferrule 26 and with the terminal pins 18establishes a hermetic seal each therebetween thereby forming the AIMDhermeticaly sealed feedthrough 14.

As further shown in FIG. 3, the filtered feedthrough assembly 22includes the externally grounded feedthrough capacitor 24 that providesfiltering of undesirable EMI signals before they can enter the AIMDcasing 32 via the terminal pins 18. The externally grounded feedthroughcapacitor 24 comprises a capacitor dielectric 48, the capacitordielectric comprising a ceramic or a ceramic-based dielectric. Thecapacitor dielectric 48 of the externally grounded feedthrough capacitor24 supports at least one active electrode plate 50 interleaved in acapacitive relationship with at least one ground electrode plate 52, andwherein the at least one active electrode plate 50 is conductivelyconnected to the conductive pathway, which is, as illustrated in FIG. 3,terminal pins 18, and the at least one ground electrode plate 52 isconductively coupled to the ferrule 26. The capacitor dielectric 48 maybe a monolithic ceramic, such as a multi-layer ceramic capacitor (MLCC),or may alternatively be stacked film, tantalum or electrolyticcapacitors. It is understood that the capacitor dielectric 48 maysupport a plurality of spaced-apart layers of active electrode plates 50or first electrode plates in spaced relationship with a plurality ofspaced apart layers of ground electrode plates 52 or second electrodeplates. Additionally, the capacitor dielectric 48 may be shaped to matchthe shape of the ferrule 26, or may alternatively have an oval, round,square or rectangular shape that either differs from, approaches, or isessentially similar to the shape of the ferrule 26. The externallygrounded feedthrough capacitor 24 may be attached to the AIMDhermetically sealed feedthrough 14 adjacent to the insulator 28 at thebody fluid side insulator surface 38 by an electrical connectionmaterial 54, such as a thermal-setting conductive adhesive, a solder,and the like. As shown in FIG. 3, it is important that the electricallyconductive material 54 contact the braze material 46 a, for examplegold, so that an oxide-resistant attachment is made as taught in U.S.Pat. No. 6,765,779, the contents of which are fully incorporated hereinby this reference. The capacitor dielectric 48 includes one or morecapacitor dielectric bores 56, the one or more capacitor dielectricbores comprising a metallization layer 57 on an inner surface of eachcapacitor dielectric bore 56, each capacitor dielectric bore capable ofreceiving a terminal pin 18. Terminal pins 18 passing through the one ormore capacitor dielectric bores 56 are electrically connected to theactive electrode plates 50 of the externally grounded feedthroughcapacitor 24 by an electrical connection material 58, such as athermal-setting conductive adhesive, a solder and the like. Theelectrical connection material 58, electrically connects the terminalpin 18 and the metallization layer 57 residing on the inner surface ofthe capacitor dielectric bore 56.

Referring once again to the filtered feedthrough assembly 22 of FIG. 3,the extremely grounded feedthrough capacitor 24 in this embodiment isdisposed on the body fluid side. This is a different location comparedto the internally grounded feedthrough capacitor 24′ of FIG. 2, which isdisposed on the device side. The advantage of having the feedthroughcapacitor on the device side is that it is inside the hermeticallysealed AIMD casing 32 and is therefore, not exposed to body fluid. It isnoted that the hermetically sealed body of the AIMD is disclosed hereinas a casing 32 instead of a housing, even though, as a general term ofart, including in the prior art, the hermetically sealed body of theAIMD is generally disclosed as a housing. Nevertheless, for particulardifferentiation between an AIMD housing and a connector housing, thepresent application specifically and consistently discloses thehermeticaly sealed body of the AIMD as an AIMD casing 32, while the useof the term “housing” is particularly disclosed in relation to theterminal pin connector 16, more specifically, to the connector housing66 of the terminal pin connector 16. Hence throughout this specificationthe hermetically sealed body of the AIMD is termed an AIMD casing 32 andthe terminal pin connector body is termed connector housing 66.Regarding feedthrough capacitors, in the case of feedthrough capacitorsresiding on the body fluid side, of significance is that regularcapacitor materials of construction are not compatible with body fluid,hence, when in contact with body fluid, its electronic component wouldrapidly short out. As such, the feedthrough capacitor of FIG. 3 is aspecially designed feedthrough capacitor specifically configured to bebiocompatible, non-toxic and biostable in the presence of body fluids.One is referred to U.S. Pat. No. 6,985,347, which describes an EMIfilter capacitor assembly that utilizes biocompatible and non-migratablematerials to adapt electronic components for direct body fluid exposure,the contents of which are fully incorporated herein by this reference.

Referring again to FIG. 3, an exemplary electrical schematic is shown.Represented are two terminal pins 18, which suggests a bipolarcapacitor, meaning there are two active terminal pins 18 passing throughthe capacitor dielectric bore 56 of the externally grounded feedthroughcapacitor 24. As the structure shown with the electrical schematic ofFIG. 3 is only a cross-sectional view illustrating a single plane of thethree-dimensional body illustrated, it is understood that the externallygrounded feedthrough capacitor 24 could alternatively be a quad polarcapacitor or a long rectangular capacitor comprising more than fourterminal pins 18 (or even n number of pins). Hence, it is understoodthat there could be many other capacitor designs other than just the twoterminal pins shown in the exemplary electrical schematic. Thisexemplary electrical schematic represents two feedthrough capacitors C1and C2, which are both disposed such that they are connected to theferrule 26 and, in turn, to the AIMD casing 32 (not shown). Feedthroughcapacitors C1 and C2 act as filters or high frequency diverters, whichprevent electromagnetic interference (EMI) originating from the bodyfluid side (the EMI can undesirably couple to implanted leads or AIMDheader block wiring) thereby, protecting such dangerous electromagneticinterference from entering into the device side of the AIMD 12 where theEMI could interfere with a sensitive AIMD active electronic circuitboard 106. Feedthrough capacitors are known in the industry asthree-terminal devices and because they have extremely low inductance,they provide very broadband filtering up to frequencies of 3 GHz-10 GHz(and even above 10 GHz). Other three-terminal capacitors will bedescribed later in the present application, including flat-thrucapacitors and some X2Y attenuator designs. Two-terminal capacitors willalso be described, including MLCCs and some X2Y attenuator designs. Itis noted that two-terminal capacitors typically do not offer filteringat extremely high frequencies, however, when carefully designed,two-terminal capacitors can be effectively used in AIMDs. It isunderstood by one skilled in the art that electromagnetic interferencecould confuse the AIMD and create various life threatening situations.This is extremely dangerous for cardiac pacemaker dependent patients whorely on pacemakers to keep their hearts beating. If the cardiacpacemaker becomes confused, it could stop stimulating the heart and thepatient would die.

FIG. 3A is very similar to FIG. 3, except that the feedthrough capacitorof the embodiment of FIG. 3A is a hybrid capacitor 24″, meaning that ithas both an external ground path, which, as shown is only one externalground path example, that comprises exemplary elements 60, 54, 46 a and26 (and 32 not shown), and an internal ground path, which, as shown isonly one internal ground path example, that comprises exemplary elements26, 18 gnd, 58, and 57. It is contemplated that the terminal pinconnectors 16 of FIG. 3 are not shown in FIG. 3A, however understoodthat the terminal pin connectors 16 can be disposed on either the deviceside or the body fluid side of the AIMD 12. It is also noted in FIG. 3Athat the body fluid side and the device side of the AIMD 12 are notlabeled, as it is also understood that the capacitor, if it is abiocompatible capacitor, could also be disposed on either the body fluidside or the device side of the AIMD. In an embodiment, the terminal pinconnectors 16 could be disposed on the side of FIG. 3A towards the AIMDactive electronic circuit board 106 (in other words, the device side).FIG. 3A is taken from FIG. 42 of U.S. Pat. No. 6,765,780, the contentsof which are fully incorporated herein by this reference.

As shown in FIGS. 1, 2, 3, 3B, 3C, 7A, 7B, 8, 9, 12, 15, 16 and 17 theterminal pin connector 16 of the present invention attaches to at leastone terminal pin 18 of the AIMD hermetically sealed feedthrough 14. Theterminal pin connector 16 may also be attached to the terminal pin 18 ofan unfiltered AIMD hermetically sealed feedthrough 14 as shown in FIG. 1or to a terminal pin 18 of the externally grounded feedthrough filtercapacitor 22, as illustrated in FIG. 2. More specifically, the terminalpin connector 16 is attached to a terminal pin distal end 62. Foridentification purposes, the terminal pin distal end\62 is defined asthe portion of the terminal pin 18 inside the AIMD casing 32 of theactive implantable medical device (AIMD) 12.

FIGS. 4, 4A-4D and 5A-5D illustrate embodiments of the presentinvention. In these embodiments, the shape of the connector housing 66of the terminal pin connector 16 may comprise a square or rectangularshape, the connector housing 66 thereby having at least two flatsurfaces, which are shown as an exterior sidewall comprising a planarsurface 88 and a planar surface 93 in the connector housing 66 of atleast FIG. 4 (note: the connector housing 66 can also have a round shapeas shown in FIG. 7C, or an oval or hexagonal shape, not shown). Theterminal pin connector 16 includes an alignment feature 75, thealignment feature of the embodiment of FIG. 4 comprising an inwardlytapering surface, which helps to guide an off-center terminal pin 18 tothe center bore diameter 92. As used herein, the term “alignmentfeature” is defined as an outwardly projecting and/or outwardlyprotruding flange, edge, rim, collar, or rib on a structure serving tolocate, register, guide and/or align a first object for attaching,connecting, or mating to a second object. The alignment feature mayeither be a continuous, a discontinuous, or a partial projection orprotrusion around the circumference or the perimeter of a connectorhousing 66. The connector housing 66 of FIG. 4 is particularly designedhaving a square or rectangular shape to intentionally narrow down and/orrestrict the width of the terminal pin connectors 16 so that they can bealigned closely together on an AIMD active electronic circuit board 106(not shown) with very close spacing (otherwise known as close pitched).This is very important particularly for high density or high countconductor pathway or terminal pin 18 assemblies, which necessitate closepitch spacing requirements (one example of an AIMD 12 having highdensity or high count conductive pathways would be spinal cordneurostimulators, which generally have more than 24 terminal pins 18).As defined herein, a square or a rectangular connector housing 66comprises at least two flat surfaces (similar to or such as theexemplary exterior planar surfaces 88 and 93 of FIG. 4) for closeplacement when multiple terminal pin connectors 16 are required in alimited space (known as close pitch), and wherein each terminal pinconnector 16 is capable of attachment to at least one circuit boardelectrical connection pad 104 either being directly physically andelectrically connected, or electrically connected by an electricalconnection material 107.

As used herein, the term “electrical connection pad” is herein definedas a small surface of metal, such as copper or other suitableelectrically conductive material, on or within a circuit board oralternatively somewhere on the perimeter edge of the thickness of aprinted circuit board that allows attaching a component to the circuitboard. An electrical connection pad 104 may comprise a circuit boardland (as shown in FIG. 7A), be part of a circuit trace (as shown in FIG.7C) or be part of the perimeter edge of the thickness of a circuit board(such as, for example, where the electrical connection pad 104 of FIG.9B resides on the perimeter edge of the thickness of the circuit board(not shown) instead of on the surface of the circuit board as shown. Theedge metallization 500 shown in FIG. 27A has either an electricalconnection pad 104 as part of the metallization structure, or the edgemetallization may be discontinuous to form an electrical connection pad104, or, instead of an edge metallization 500, the perimeter edge maycomprise an electrical connection pad 104 (a perimeter edge comprisingan electrical connection pad 104 does not necessarily require an edgemetallization 500).

As shown in FIG. 4, the alignment feature 75, which is shown as adiscontinuous flange projecting from each one of the pair of the housingplanar surfaces 93 of the connector housing 66, allows for the alignmentfeature 75 of the terminal pin connector 16 to be positioned such thateither one or the other of the two discontinuous flanges overhanging theAIMD active electronic circuit board 106 (not shown) places itsassociated housing planar surface 93 directly against (and in electricalconnection to) the circuit board electrical connection pad 104. Thehousing planar surface 93 of the connector housing 66 of the terminalpin connector 16 can be directly physically connected to the circuitboard electrical connection pad 104 by an electrical connection material107. The central axis A-A of the clip through-bore 72 and the connectorhousing through-bore 78 of the terminal pin connector 16 as illustratedin FIG. 4 is the axis along which the terminal pin 18 will be inserted.

As illustrated in FIGS. 3, 3B, 3C, 3D, 4, 4A-4C, 5A-5E, 6A-6C theterminal pin connector 16 comprises a clip 64 that resides within aconnector housing 66. The clip 64 is designed to accept terminal pin 18so that, when the terminal pin 18 is inserted into the terminal pinconnector 16, the clip 64 surrounds the circumference or perimeter ofthe terminal pin 18 such that the clip 64 grasps the exterior surface ofthe terminal pin 18 by at least one prong 70. In the embodiment shown inFIGS. 4, 4A-4C and 5A-5D, the clip 64 comprises a clip base 68 and aplurality of prongs 70 that extend from the clip base 68. Clip 64 maycomprise a single construction, the clip further comprising a singlematerial, as indicated in the cross-sectional view of FIG. 6B (clip 64is shown having the same cross-hatch for the clip base 68 and the prong70). Alternatively, the clip 64 may comprise multiple components, andmultiple materials, for example, the clip base 68 may be one componentand one or more prong 70 each may be a different component, wherein theclip base 68, and the one or more prongs 70 are each of a differentmaterial. As shown, the clip base 68 comprises a clip sidewall 72,which, in this case, is annular. The exemplary annular dip sidewall 72comprises a clip through-bore 74. This clip through-bore 74 is theopening that accepts the terminal pin 18 such that terminal pin 18longitudinally extends and is grasped by prong(s) 70 of the clip 64. Theclip through-bore 74 is dimensioned such that the terminal pin 18 of amultitude of diameters can pass therethrough with an interference fitmaking electrical contact between the terminal pin 18 and the clip 64.

Referring once again to prong 70, shown in FIGS. 4A-4C, is that the clip64 comprises at least one prong 70 or finger that extends from the clipbase 68. As shown, the prongs 70 are preferably angled inwardly towardsa central (longitudinal) axis A-A that extends longitudinallythrough/along the clip through-bore 74 of the clip base 68. This inwardorientation enables the prongs 70 to flex and make contact to compressagainst the exterior surface of the perimeter of the terminal pin 18gripping the terminal pin 18 therewithin.

In addition, the inward orientation of the prongs 70 creates a wedgingrelationship between the terminal pin 18 and prongs 70. As the end ofthe prongs 70 compress against the sidewall of the terminal pin 18, thepin 18 becomes wedged against the prongs 70. The wedging of the prong 70against the terminal pin 18 importantly assures that a very lowresistance electrical connection will be achieved. It is very importantthat a reliable and very low resistance connection be achieved from thecircuit board to the connector housing 66 to the clip 64 and in turn, tothe prong 70 and to the terminal pin 18. This path is highly conductiveboth at DC and at RF frequencies. Such a wedging relationship helpsprevent the terminal pin 18 from inadvertently disengaging with the clip64. However, in the embodiments shown in FIGS. 4-6 the terminal pins 18can be removed from the clip 64 when necessary such that the terminalpins 18 can be inserted and removed from the clip 64, for example, whenAIMD active electronic circuit board 106 replacement is deemednecessary.

Regarding the clip 64 and terminal pins 18 of FIGS. 4A through 6C, aterminal pin(s) 18 can freely slide longitudinally within the prong(s)70 along axis A-A without disengaging from the terminal pin connector(s)16 even though the terminal pin(s) 18 is gripped tightly by the prong(s)70. This is extremely important, especially during final laser weldingof the AIMD casing 32 of the active implantable medical device 12,because once the AIMD feedthrough connector assembly 10 is installed toa first casing half 112, and the AIMD active electronic circuit board106 is plugged in using the terminal pin connector(s) 16 residing on thecircuit board, a final laser weld is performed to complete a hermeticenclosure (that is, the AIMD casing 12), which now comprises the AIMDfeedthrough connector assembly 10 and the two AIMD can halves (that is,the first casing half 112 and the second casing half 114). The finallaser weld introduces heat, which can create significant stress in anassembly, a subassembly, or between components that are not free tomove, due to differences in the coefficient of linear thermal expansion(CTE), a material property of each component of the AIMD 12. Since CTEis a material property, different materials will expand on heating atdifferent rates, depending on a material's composition, structure, andthermal properties. When CTE mismatch exists, for example, between theAIMD active electronic circuit board 106, the circuit board holdingfixture and the AIMD casing halves 112, 114, there is a higher potentialfor developing fractures, cracks, delamination and detachment within anassembly. In the exemplary case of final laser welding, as the AIMDcasing 32 expands and contracts, the terminal pin(s) 18 are capable ofsliding within the prong(s) 70 without disengaging from the terminal pinconnector(s) 16, thereby preventing the buildup of stresses at thisconnection. This is of particular benefit, in that, when terminal pin(s)18 are welded or soldered to an AIMD component or subassembly, such asan AIMD active electronic circuit board 106, an EMI filter board 106′,an AIMD header block 118, or combinations thereof, the weld or solderjoint could lead to fracture, cracking, delamination or detachmentresulting in failure and rejection of the final laser welded AIMDassembly, along with all the subassemblies and components that are nowhermetically sealed within the AIMD casing 32.

Further referring to clip 64, as a terminal pin 18 is introduced throughthe clip base 68 of the clip 64, the space between the prong(s) 70expands to thereby allow the terminal pin 18 to proceed therebetween. Inthe embodiment shown in FIG. 3, the prongs 70 of the clip 64 aredesigned to allow the terminal pin 18 to proceed in one directionbetween the prong ends such that the terminal pin 18 is prohibited frommoving in the reverse direction. In these embodiments, the terminal pin18 proceeds in a distal direction through the clip through-bore 74residing within the connector housing 66 of the clip 64. Once positionedwithin the clip through-bore 74, the angled prong orientation gripsterminal pin 18 and inhibits or prevents the terminal pin from markedlymoving in the reverse proximal direction mitigating disengagement fromthe terminal pin connector 16.

FIG. 3B illustrates an alternative embodiment of clip 64 and connectorhousing 66 of terminal pin connector 16 of the present invention. Asshown, at least one prong 70 extends from the base 68 of the clip 64. Inaddition, the connector housing 66 comprises a housing opening 67 thatat least partially extends through the thickness of the connectorhousing 66 from a first connector housing end 59 towards a secondconnector housing end 69. On the right-hand side of FIG. 3B, the housingopening 67 has a first diameter that extends through the first connectorhousing end 59. On the left-hand side of FIG. 3B, the housing opening 67extends axially along longitudinal axis A-A through at least a portionof the connector housing thickness to a connector housing end wall 65located at the second connector housing end 69, thereby forming a blindhole within the connector housing 66. As defined herein a “blind hole”is a hole that is formed, such as by reaming, drilling, or milling, to aspecified depth without breaking through a connector housing end wall 65of the workpiece. Accordingly, the terminal pin distal end 62 is atleast partially positioned within the housing opening 67 of the blindhole shown, thereby positioning the terminal pin 18 such that a lengthof terminal pin 18 extends along longitudinal axis A-A. The terminal pindistal end 62 when inserted into the blind hole housing opening 67further positions terminal pin 18 proximate a connector housing interiorsurface 63 such that the terminal pin distal end 62 may be optionallybottomed out (or contacting) the connector housing end wall 65.Referring once again to the left-hand side of FIG. 3B, one can see thatwhen terminal pin 18 is bottomed out against the connector housing endwall 65 of the blind hole, the terminal pin 18 cannot be inserted anyfurther into the terminal pin connector 16. Consequently, in theembodiment shown on the left-hand side of FIG. 3B, the terminal pindistal end 62 cannot extend past the blind hole because the connectorend wall 65 stops any further insertion movement. Hence, the blind holeon the left-hand side of FIG. 3B is an important feature in that theprong 70 cannot fully slide over the rim of the terminal pin ridge 73,which could thereby challenge or otherwise inhibit removal orreplacement of a defective circuit board. The terminal pin ridge 73 alsoadvantageously imparts added deflection of prong 70, which enhances gripthereby ensuring a high reliability, low resistance, low impedance and aremovable electrical connection. Now referring to the right-hand side,FIG. 3B illustrates prong 70 engaging the terminal pin recess 71. Thetransition corner from the diameter of terminal pin 18 to the terminalpin recess 71 is curved and radiused to facilitate terminal pin 18removability from clip 64 even though terminal pin 18 may extend throughand optionally outwardly beyond the connector housing through-bore 78 ofthe connector housing 66. The curved and radiused portion of theterminal pin recess 71 provides a smooth surface on which terminal pin18 can slide in and out of dip 64 when a push or a pull force isapplied. Hence, the connector housing end wall 65, which forms a blindhole on the left-hand side of FIG. 3B in the connector housing 66, isnot important or even necessary, and therefore may only optionally beincluded. Referring back to the right-hand side of FIG. 3B, theembodiment illustrated lacks the connector housing end wall 65 shown inthe left-hand side of FIG. 3, and instead comprises the connectorhousing through-bore 78. In this case, the terminal pin distal end 62optionally protrudes outwardly beyond the terminal pin connector 16.This can be an important feature during final visual inspection of theassembled AIMD active electronic circuit board 106 and AIMD hermeticallysealed feedthrough 14 as the protruding terminal pin distal end 62provides a visual indicator to making sure that al of the terminal pins18 are fully inserted into their respective terminal pin connectors 16.

In addition, at least one prong 70 is shown extending distally from theannular clip sidewall 72. The end of the at least one prong 70 contactsa portion of an exterior surface of the terminal pin 18 along theterminal pin distal end 62 that resides within the housing opening 67.The prong 70 is angled inwardly towards the central axis A-A thatextends longitudinally through the clip through-bore 74 of the base 68and into the blind hole of the housing opening 67. As previouslymentioned, this inward orientation enables the prong 70 to contact andcompress against the exterior surface of the perimeter of the terminalpin 18 gripping the terminal pin 18 therewithin. Furthermore, the prong70 creates a wedging relationship between the exterior surface of theterminal pin 18 and the annular clip sidewall 72.

In some embodiments, a terminal pin recess 71 as shown on the right-handside of FIG. 3B, may partially extend within an exterior surface ofterminal pin 18 about the terminal pin distal end 62 thereof. Theterminal pin recess 71 of FIG. 3B is shown positioned such that therecess annularly extends around the circumference (the exterior surface)of the terminal pin distal end 62 of terminal pin 18. The terminal pinrecess 71 may enhance the grip of the prong 70 along the terminal pin'sexterior surface as the terminal pin recess 71 provides a groove withinthe exterior pin surface so that the end of the prong 70 can bepositioned therewithin.

Alternatively, in lieu of the terminal pin recess 71, an outwardlyextending terminal pin ridge 73 may be at least partially constructedabout the terminal pin distal end 62 of the terminal pin 18. Referringonce again to features 71 and 73 of FIG. 3B, the terminal pin recess andthe terminal pin ridge are desirably radiused such that a defectivecircuit board with applied pull force, could still be removed from thethe terminal 18 pins such that a replacement or reworked circuit boardcan be installed. As shown on the left-hand side of FIG. 3B, theterminal pin ridge 73 may be positioned annularly extending around thecircumference (the exterior surface) of the terminal pin distal end 62of terminal pin 18 similarly to the terminal pin recess 71. Also,similarly to the recess 71, the terminal pin ridge 73 helps preventinadvertent disengagement of the prong(s) 70 of the clip 64 from theterminal pin 18. When the terminal pin 18 is positioned within theconnector housing 66, the terminal pin ridge 73 is positioned proximalthe end of prong 70.

Referring once again to FIG. 3B, on the left-hand side, one will seethat the ring has curved and radiused surfaces (convex shaped).Referring to the right-hand side, one will see that the angular notch isalso curved and radiused (concave shaped). This is to allow the terminalpin 18 to be retracted when a pull force is applied. The curves aredesigned such that the prong 70, will still slip over or into theconcave or convex shapes respectively even when the concave or convexshapes induces resistance to such movement. It is contemplated that, forexample, on the right-hand side of FIG. 3B, the notch could be arectangular notch instead of the concave shaped curved notch, as shown.In the case where the notch is rectangular, the resistance to pull maybe increased such that a tool may be required for disengaging andretracting the terminal pin 18 from the terminal pin connector 16. Inthis case, it would be grip-tight, but still optionally be removablewith the help of a tool.

Referring once again to FIG. 3B, on the left-hand side, one can see thatthe prong 70 overlies the terminal pin ridge 73. Importantly, theterminal pin distal end 62 of the terminal pin 18 inserted into theterminal pin connector 16, which extends fully through the feedthroughcapacitor connector assembly 20 including the filtered feedthroughassembly 22, is designed such that the terminal pin distal end 62bottoms out at the connector housing interior surface 63 of the blindhole of the connector housing 66. This feature is very important becausethat means that the prong 70 is pushed against the outside radius ofterminal pin ridge 73. This has two very important results. The firstresult is that the terminal pin ridge 73, as it is shown positioned,facilitates retraction of a circuit board (such as an AIMD activeelectronic circuit board 106 or an EMI filter circuit board 106′ notshown). As described throughout the specification, the connector housing66 is designed to be mechanically and electrically attached to a circuitboard land or a circuit trace of an AIMD active electronic circuit board106 or an EMI filter circuit board 106′ (not shown). Once the AIMDactive electronic circuit board 106 or the EMI filter circuit board 106′Is installed and the flange 30 of the ferrule 26 is laser welded intothe AIMD casing 32, longitudinal movement of terminal pin 18 isrestricted. So, it is really only during circuit board installation andremoval that the terminal pin 18 slides in and out of the connectorhousing 66 comprising clip 64 and its associated prong(s) 70. As such,the curved and radiused feature of both the left-hand and the right-handsides of FIG. 3B positions the prong(s) 70 such that the AIMD activeelectronic circuit board 106 is removable thereby allowing replacementor rework and re-installation of the circuit board in the case thecircuit board is deemed defective. Optionally, not shown, a secondarytool could be used to assist release of prong(s) 70 from the terminalpin(s) 18 thereby facilitating removal of the AIMD active electroniccircuit board 106 for replacement or rework and re-installation.

Referring to U.S. Pat. No. 9,692,173, one will see that FIG. 3B of thepresent specification is identical to FIG. 3 of the '173 patent, whichis in the present priority chain and is further incorporated herein bythis reference. One will see that the terminal pin connector 16 has oneor more prongs 70 that engage terminal pin 18. In this case, terminalpin 18 has been specially formed or machined. This provides movementresistance to terminal pin 18 when prongs 70 engages terminal pin 18,thereby forming a grip-tight relationship between the prongs 70 and themachined feature in terminal pin 18. This is to help prevent inadvertentmovement of the terminal pin 18 along the longitudinal axis A-A out fromwithin the connector opening 67, while still allowing for terminal pin18 removability.

Referring once again to FIGS. 3, 3B and 3C, as these are cross-sections,the characteristics of the clip through-bore 74 only illustrates asingle plane of the through-bore, hence, to better appreciate thefeatures and functionality of the clip through-bore 74, one is referredto FIGS. 4A through 4C and FIGS. 5A through 5C.

In any of the embodiments herein, the clip 64 or connector housing 66may comprise an electrically conductive material, such as anelectrically conductive metal. For example, the clip 64 may comprisecopper, tin, iron, steel, stainless steel, aluminum, titanium, gold,silver, platinum, palladium, rhodium, brass, molybdenum, tungsten,niobium, and alloys and/or combinations thereof; constantan, berylliumcopper, beryllium nickel, Nitinol, aluminum alloys, titanium alloys,gold alloys, sliver alloys, platinum alloys, palladium alloys, copperalloys, tin alloys, rhodium alloys, niobium alloys, nickel-chromiumalloys, associated alloys and combinations thereof; electricallyconductive carbons, including the ‘super’ carbon developed by theinternational collaboration between Yanshan University and the CarnegieInstitution of Science, the ‘super’ carbon being hard, elastic likerubber, ultrastrong, lightweight and electrically conductive; andelectrically conductive composites, the electrically conductivecomposites being made from two or more constituent materials that havedifferent physical and chemical properties, such that, when combined,produce a composite material with characteristics different from theindividual components, and which can be customized to specificallyaddress, for example, degree of electrical conductivity, thermalmanagement, electrical and/or magnetic field management, electromagneticinterference (EMI) mitigation, noise susceptibility shielding, weight,cost, and other such material property requirements. Any of thesematerials may be used alone or in combination with each other. Clip 64may also comprise a plating, wherein the plating may further compriseelectroplating, electrodeposition, electroless plating, barrel plating,or mechanical plating. The plating may be provided to increase strengthand durability, allow solderability if needed, improve electricalconductivity, increase surface hardness, provide wear resistance, impartanti-galling properties, afford antifriction properties, offerinsertion/retraction lubricity, or increase friction to impartresistance to movement or to enhance grip, or permit propertycustomization of clip 64 to address a specific requirement of animplantable medical application. The plating may comprise gold, silver,palladium, rhodium, platinum, titanium, aluminum magnesium, tin, copper,zinc, nickel, chrome, stainless steel, bronze and combinations thereof.The plating may further comprise palladium/nickel, palladium/cobalt,tin/lead, zinc/nickel, zinc/cobalt, alloy plating, composite plating, orcombinations thereof. Additionally, clip 64 may comprise a gold flashover any plated material, for example, steel with a tin plating, nickelplated steel, aluminum with electroless nickel plating, beryllium copperwith gold over copper plating, brass with a tin plating, brass with goldover a copper plating, copper alloy with gold over copper plating,phosphor bronze with gold over copper plating, zinc plating with achromate seal, zinc plating with a tin plating, passivated stainlesssteel and combinations thereof.

In preferred embodiments of the present application, it would bedesirable if the connector components, including the connectorassemblies, prongs, fingers, tines, clips and the like, consistprimarily of non-ferromagnetic materials, so that patients having AIMDimplants can undergo magnetic resonance imaging (MRI) when indicated.For example, it is now possible to obtain pacemakers, implantablecardioverter defibrillators, and even neurostimulators that have been“MRI Conditionally Approved” by the FDA. In an MRI environment, whenAIMDs comprise components having a lot of magnetic and/or ferromagneticmaterial, the presence of such magnetic and/or electromagnetic materialscan be problematic for a number of reasons. These include: 1) increasedforce and torque on the AIMD due to the static magnetic field of theMRI; 2) increased image artifact in the immediate area of the AIMDcaused by the interaction of the MRI fields with the ferromagneticmaterials and dipole movements; and 3) during RF field exposure fromMRI, components that have high magnetic and/or ferromagnetic materialscan exhibit undesirable heating through dipole flipping. Therefore,non-magnetic and/or non-ferromagnetic materials are excellent optionsfor addressing these issues. As used herein, magnetic materials orferro-magnetic materials mean any materials that are attracted to amagnetic force or highly saturate in the presence of a magnetic field.Non-magnetic or non-ferromagnetic refers to those materials which areeither not attracted or only weakly attracted to a magnetic force, andwhich either do not or minimally saturate in the presence of a magneticfield. Nonlimiting examples of non-ferromagnetic materials include:aluminum, beryllium, copper, gold, lead, platinum, rhodium, sliver, tin,titanium, zinc, and alloys or combinations thereof. Also included arebrass, bronze, 304 stainless steel, 316 stainless steel and the like.Any of these materials can also be used to coat, plate or otherwisecover any of the listed materials above.

Alternatively, the clip 64 may have an electrically conductive coating,such as an electrically conductive foil, metallization, plating or vapordeposited film. Coating processes may include: physical vapordeposition, chemical vapor deposition, electrostatic spray assistedvapor deposition (ESAVD), electron beam physical vapor deposition(EBPVD), ion plating, ion beam assisted deposition (IBAD), magnetronsputtering, pulsed laser deposition, sputter deposition, vacuumdeposition, pulsed electron deposition (PED), plating, electrolessplating, electroplating, spraying, painting, plasma spraying, thermalspraying, spin coating, dip coating, metal foil lamination, and thinfilm deposited layers. The electrically conductive coating may compriseone or more layers. The electrically conductive coating may comprise,but not limited to, copper, tin, stainless steel, aluminum, titanium,gold, platinum, palladium, carbon, palladium alloys, associated alloysand combinations thereof. The clip 64 (base 68 and prong(s) 70) isdesigned to provide an electrical connection between the terminal pin 18of the AIMD hermetically sealed feedthrough 14 and the connector housing66.

Referring now to FIG. 3D, shown are embodiments of the terminal pinconnector 16 of the present invention disposed on the terminal pindistal ends 62, 62′ of the terminal pin 18 on the device side. Aspreviously disclosed, the terminal pin connectors 16 would be mountedand electrically attached to AIMD active electronic circuit board landsor circuit traces. Mounting of terminal pin connectors 16 to circuitboard lands or circuit traces is more thoroughly disclosed in FIGS. 7A,7B, 8 and 9. Referring once again to FIG. 3D, illustrated is an AIMDhermetically sealed feedthrough 14 to which an externally groundedfeedthrough capacitor 24 is mounted, thereby forming a filterfeedthrough. The purpose of feedthrough capacitors is to decouple ordivert dangerous electromagnetic interference (EMI) signals that may bepicked up on the body fluid side of the AIMD 12 by the implanted leadsconnected to the header block of the AIMD. The terminal pin connectors16 of the present application, which are located and mounted on an AIMDactive electronic circuit board (not shown), are disposed such that theterminal pins 18 of the filter feedthrough are capable of literallyplugging into their respective terminal pin connectors 16 so that theterminal pin connectors 18 are adjacent the feedthrough capacitor 24.

Referring once again to FIG. 3D, illustrated is a laser weld 116′ thatconnects the flange 30 of the ferrule 26 to the AIMD casing 32, which isgenerally of titanium. During AIMD pulse generator assembly, a tackweld, as opposed to a continuous laser weld, is made to hold the ferruleinto an AIMD first casing half or clam shell. After AIMD activeelectronic circuit board testing and acceptance, then an AIMD secondcasing half is mated to the first casing half and a continuous laserweld is made all around the can halves and around the flange 30 of theferrule 26, thereby, completely hermetically sealing the AIMDelectronics battery and associated components within the AIMD casing 32.

Referring once again to FIG. 3D, illustrated embodiments of the twoterminal pins 18, both of which are hermetically sealed to the insulator28. The ferrule 26 is also hermetically sealed to the insulator 28. Theterminal pins 18 pass through the insulator 28 in non-conductiverelation with the ferrule. A ground pin 18 gnd (not shown) may alsooptionally be electrically and mechanically connected to the ferrule.Referring now to the terminal pin distal ends 62, 62′, Illustrated onthe left-hand side is an embodiment of a terminal pin distal end 62 thatis pointed [which may alternately be rounded (not shown)] thereby,facilitating insertion into the terminal pin connector 16. On theright-hand side, illustrated is an embodiment of a terminal pin distalend 62′ that is flat, in other words, squared off [the corners of whichmay alternately be radiused (not shown) to eliminate sharp corners].Either of these two terminal pin distal end embodiments will facilitateinsertion of the terminal pins 18.

FIG. 3D also illustrates two terminal pin connector 16 embodiments. Theembodiment on the right-hand side of FIG. 3D illustrates an entryportion of the through-bore of the connector housing 66 comprising asmooth transition 164 to help guide the flat terminal pin distal end 62′into the terminal pin connector 16. It is possible that, for the uniqueapplication of an active implantable medical device, in order to plug inan AIMD active electronic circuit board (not shown), the circuit boardmay be tilted at a slight angle relative to the terminal pins 18 of thehermetically sealed feedthrough 14. Therefore, the smooth transition 164of the terminal pin connector 16 shown on the right-hand side of FIG. 3Dis a configuration for effectively guiding the terminal pin 18 when theterminal pin is not perfectly parallel to and/or coaxially aligned withthe connector housing 66 so that the terminal pin 18 can be securelygripped within the prongs 70 of the dip 64.

The embodiment on the left-hand side of FIG. 3D illustrates a connectorhousing 66 comprising a chambered entry portion an a clip 64 residingwithin the connector housing 68 wherein the entry portion of thethrough-bore of the clip 64 comprises a radiused edge 166. Accordingly,this embodiment is an alternate configuration for effectively guidingthe terminal pin 18 into the clip 64 so that the terminal pin 18 can besecurely gripped with the prongs of the clip 64. In this embodiment, apointed (or rounded) terminal pin distal end 62 would work in concertwith the radiused edge 166 of the clip 64 in facilitating insertion ofan off-centered terminal pin 18. It will be understood by one skilled inthe art, that any of the embodiments taught herein to facilitateterminal pin connector insertion can be used concurrently or in variouscombinations pending application requirements.

The present invention is a continuation-in-part application to U.S. Pat.No. 10,587,073, which resides in a family that includes U.S. Pat. Nos.9,065,224 and 9,692,173, the contents of which all are fullyincorporated herein by this reference. The following is quoted from theAbstract of the '224 patent: “The connector clip mechanically attachesto the terminal pin of the feedthrough and exterior surface of thehousing electrically contacts the circuit board, creating an electricalconnection therebetween.” This is a general description of the presentinvention and covers terminal pin connector 16, wherein a through-pin 18connected to the terminal pin connector 16 is insertable into andretractable from its terminal pin connector 16, thus removable. Someembodiments of the terminal pin 18 of the present application providefor a terminal pin 18 residing within a terminal pin connector 16 suchthat the terminal pin 18 is grasped in a grip-tight manner such thatinadvertent longitudinal movement is prevented while still allowingremovability of the terminal pin 18 from the terminal pin connector 16when a pull force is applied. Now quoting from column 4 lines 58 and onfrom the '224 invention, we have, “as illustrated in FIGS. 4, 4A-4C and5A-5C, the terminal pin connector 16 comprises a clip 64 that resideswithin a connector housing 66. The clip 64 is designed to be positionedaround the perimeter of the terminal pin 18 such that, the clip 64grasps the exterior surface of the terminal pin 18.” This is a veryclear description of FIG. 3D of the present invention. Referring onceagain to FIG. 3D, the clip or prongs 64, 70 reside within the connectorhousing 66 wherein, the clip and its prong 70 are, “designed to bepositioned around the terminal pin 18 such that, the clips 64 grasp theexterior surface of the terminal pin 18.” This is a description of anembodiment that allows longitudinal movement of the pin 18 within theterminal pin connector 16. Again, quoting from column 4 of the '224invention, from line 65 and on, “the base through-bore 74 is dimensionedsuch that, the terminal pin 18 of a multitude of diameters can passtherethrough.” Hence, the terminal pin connector 16 can accommodateinsertion and retraction of a family of terminal pin 18 diameters in theevent a defective component connected by terminal pin connector 16requires replacement or rework. Quoting from column 5 of the '224invention, starting on line 1, stated is, “As shown in FIGS. 4A-4C, theclip 64 comprises at least two prongs or fingers 70 that extend from thebase 68. As shown, the prongs 70 are preferably angled inwardly towardsa central axis A-A that extends longitudinally through the clipthrough-bore 74 of the base 68. This inward orientation enables theprong 70 to contact and compress against the exterior surface of theperimeter of the terminal pin 18 gripping the pin therewith.” This isthe description in the present invention of FIG. 3D where the prong 70grips the exterior of the terminal pin 18.

Referring now to FIG. 3B, one can see that features 73 and 71 of theterminal pin 18 are curved. This curved feature mitigates inadvertentlongitudinal movement of the terminal pin 18 out of the terminal pinconnector 16, however is still removable with an applied pull force,thereby allowing replacement or rework of a defective componentconnected by terminal pin connector 16.

Referring once again to the '224 specification column 5, line 11, itsays, “The prong 70 of the clip 64 are preferably designed to allow theterminal pin 18 to proceed in one direction between the prong ends suchthat, the terminal pin 18 is prohibited from moving in the reversedirection.” Referring to FIGS. 4A-4C of the present application to whichthis language refers, illustrated are embodiments of the prongs 70 ofthe clip 64 through which the terminal pin 18 proceeds. FIG. 4Acomprises three prongs, FIG. 4C comprises two prongs and FIG. 4Ccomprised four prongs. As the terminal pin 18 is intended for insertioninto the terminal pin connector 16 by way of the through-bore of thebase 68 of the clip 64 as shown, retraction would be prohibited unless acomponent attached by the terminal pin connector 16 is defective andrequires removal for replacement or rework. Hence, the term “prohibit”means that an inserted terminal pin 18 is not to be retracted fromterminal pin connector 16 unless the component connected by the terminalconnector is deemed defective and requires removal for replacement orrework. As such, a designer would consider a desired grip strength whendesigning prong 70 of clip 64 such that terminal pin 18 is preferablyprohibited from moving in the reverse of the insertion direction unlessretraction is required due to defect. If a component is deemeddefective, the pull force required for retraction from the terminal pinconnector must be greater than the push force required to insert theterminal pin 18 into the terminal pin connector 16. Embodiments aredisclosed herein, wherein the design of one of a terminal pin, aterminal pin connector, a clip of a terminal pin connector, a prong of aclip of a terminal pin connector, a compliant termination structure, orcombinations thereof consists of a pull force for retraction greaterthan a push force for insertion. In some embodiments, a tool is used tofacilitate retraction. In other embodiments a memory-shape alloy may beused to facilitate retraction.

Now referring again to FIG. 3, one can see that the terminal pins 18 are“preferably designed” such that the terminal pins themselves 18 arealternatively notched to thereby engage the prong 70. As can be seen inFIG. 3, the terminal pins 18 and their distal end 62 are easily insertedthrough the prongs 70, but once the prongs engage the terminal pin,which optionally has a machined recess, then the prongs engage the pinin such a way that they prohibitively retractable without using a tool.This embodiment can be extremely important especially when the terminalpin connectors 16 are disposed on the device side of the casing 32.

Referring to FIGS. 4, 4A-C, 5A-C and 6B, the connector housing 66 maycomprise a housing sidewall 76 which encompasses a connector housingthrough-bore 78 along the A-A axis that extends longitudinallytherethrough, or at least partially therethrough when the connectorhousing 66 comprises a blind hole. In the embodiments shown, theconnector housing 66 is designed similarly to that of a tube having anopening that extends from a proximal housing end 80 to a distal housingend 82. The connector housing 66 comprises a housing sidewall thickness84 that extends from a housing interior sidewall surface 86 to a housingexterior sidewall surface 88. In certain embodiments, the terminal pinconnector 16 may have a terminal pin connector length 90 ranging fromabout 0.025 Inches to about 0.300 inches and a through-bore diameter 92that ranges from about 0.01 Inches to about 0.030 inches.

As shown and taught, the clip 64 is positioned within a connectorhousing 66 by an interference fit. This interference fit configurationprevents the clip 64 from moving inward or outward of the connectorhousing 66 when insertion or retraction of the terminal pin 18 occurs.Instead of an interference fit, it is contemplated that the individualclip 64 can be positioned within the connector housing 66 and thenelectrically and mechanically attached through various processes,including soldering, welding, brazing and the like. It will be furtherappreciated that these structures, such as the clip 64, may be formed by3D printing processes. The clip 64 and the connector housing 66 could be3D printed as a monolithic structure or as two separate pieces, whichare subsequently joined, as described above. 3D printing includesstereolithography 3D printing. Additionally, the clip 64 and connectorhousing 66 could comprise a single co-sintered metal. Furthermore, ashape-memory alloy, such as Nitinol, may be used for clip 64, whereinthe insertion could be done at one temperature and then the Nitinolwould expand when it reaches body temperature. If Nitinol is used, theNitinol can further be modified as described earlier to impart differentspring constants at different points of the clip 64′.

Referring to FIG. 4, illustrated is an embodiment of the connectorhousing 66 comprising a housing perimeter. The housing perimetercomprises four planar surfaces comprising two planar pairs, each planarpair of the planar surfaces having planes opposite each other. A firstplanar pair comprises housing planar surfaces 88, the planes of whichare depicted in FIG. 4 at the ‘right-hand side’ labelled 88 and at the‘left-hand side’ (not labelled) of the terminal pin connector 16. Asecond planar pair comprises housing planar surfaces 93 the planes ofwhich are depicted in FIG. 4 at the ‘top’ labelled 93 and at the‘bottom’ (not labelled) of the terminal pin connector 16. It iscontemplated that angled, curved or radiused transitions 100 from onehousing planar surface 88 to another housing planar surface 93 may beincluded as illustrated for the purpose of eliminating corners.Alternatively, the connector housing 66 of the terminal pin connector 16may comprise fewer than four or more than four planar surfaces, such asmay occur in, for example, triangular or hexagonal connector housingshapes. It is contemplated that the connector housing 66 could be round,which would eliminate planar surfaces 88 and 93.

In summary, the connector housing 66 as illustrated in FIG. 4, iselectrically connected to a circuit board electrical connection pad 104.Therefore, the terminal pin connector 16, comprising the connectorhousing 66 and the clip 64 (with a base 68 and/or prongs 70) are all inelectrical contact to the circuit board electrical connection pad 104.When the AIMD active electronic circuit board 106 is plugged into eithera filtered or an unfiltered AIMD hermetically sealed feedthrough 14,this establishes an electrical connection between the terminal pins 18through the terminal pin connector 16 to the circuit board electricalconnection pads 104. These circuit board electrical connection pads 104would each be routed through either internal or external AIMD activecircuit board 106 conductive paths such as circuit traces. Theconductive paths comprise one of an active conductive path, a groundconductive path, or both an active path and a ground path. Theseconductive paths are not shown for simplicity.

FIG. 5D is very similar to FIGS. 4A, 4B, 4C and FIGS. 5A, 5B and 5C.FIG. 5D shows the terminal pin 18 ready to be inserted inside theconnector housing 16, as illustrated. Once the terminal pin 18 isinserted, the prong(s) 70 deflect (there must be at least one prong). Itis important that the material of the prongs 70 have a spring constantsuch that, once the terminal pin 18 is inserted, the prongs tightlygrasp the outside diameter of the terminal pin 18, thereby providing alow resistance/low impedance electrical connection and a robustmechanical connection. Referring once again to FIG. 5D, in thisembodiment, there is a blind hole with a connector housing end wall 65.It is contemplated that the connector housing 66 could also be anopen-bore or through-bore. In FIG. 5D, the terminal pin 18 shown is aformed pin (generally drawn and extruded), which, once the terminal pinis slipped tightly within the prong 70, the terminal pin 18 can beremoved. In other words, a defective circuit board to a terminal pinconnector 16 is attached (not shown) would be removable for replacementor rework.

FIG. 5E is very similar to FIG. 5D, except that prong 70 has beenreplaced by a spring clip 64′. Instead of prong 70, the spring clip 64′residing within the connector housing 66 comprises a clip base at eachend and one or more elongated members therebetween so that the insidediameter formed by the elongated members is less than the insidediameter of the clip bases. The one or more elongated members areconnected to each clip base. While it is preferable for the spring clip64′ to comprise multiple elongated members, some applications mayalternatively allow the clip bases to be connected by a single compliantelongated member connected to the clip bases at each end of the springclip 64′. The material of spring clip 64′ has a spring rate such that itwill expand as the terminal pin 18 is being inserted. Therefore, one hasto insert the terminal pin connector 16 (and circuit board not shown)onto terminal pin 18 and then apply a push force such that the side wallor walls of the elongated members of the clip spring 64′ of terminal pinconnector 16 expands and then grips against the terminal pin 18, therebyforming a very low resistance and low impedance electrical connection.Referring once again to FIG. 5E, in order to facilitate flexure, thestructure 64′ having a single elongated member, the single elongatedmember between the clip bases being continuous around the fullcircumference of the clip bases, however, in this case the singlecontinuous elongated member also comprises an elongated member wallthickness less than the wall thickness of the base clips. It iscontemplated in FIG. 5E, that the cross section shown may be understoodto illustrate a single continuous elongated member or two or more, even“n” number of separate elongated members. Referring once again to FIG.5E, one will appreciate that the overall length L of the spring clip 64′can be adjusted so that a desired electrical contact force to theterminal pin 18 is made. The number of elongated members can also beadjusted (as a high number of elongated members will require lesscontact force while a smaller number of elongated members will requirehigher contact force).

Referring once again to FIG. 5E, it is contemplated that the spring clip64′ is electrically and mechanically connected to the inside diameter ofthe connector housing 66 of the terminal pin connector 16. The connectorhousing 66 could be angled inward (chamfered) so that the spring clip64′ compresses while it is being inserted or a tool could be used,similar to a piston ring compressor for the pistons of an automobile.One could also use a shape-memory alloy for any of the configurationsjust described, such as Nitinol, wherein the insertion could be done atone temperature and then the material would expand when it reaches bodytemperature. If Nitinol is used, the Nitinol can further be modified asdescribed earlier to impart different spring constants at differentpoints of the spring clip 64′.

In an embodiment (not shown), it is understood that the structure ofFIG. 5E illustrating the spring clip 64′ could also be inserted into abore or a counterbore of a co-sintered conductive via (for example, seeFIGS. 22 and 23).

As illustrated in FIG. 7A, the housing bottom planar surface 98 (hiddenunderneath) of the connector housing 66 is designed to establishintimate electrical contact with an electrical connection pad 104 of anAIMD active electronic circuit board 106 of the active implantablemedical device 12. As such, the connector housing 66 may be composed ofan electrically conductive material or alternatively may be coated withan electrically conductive material, such as an electrically conductivefoil, metallization, plating or vapor deposited film as previouslydisclosed for clip 64. The coating may additionally be used tofacilitate joining processes, such as soldering or even welding. Thecoating may also comprise any one or more of the materials previouslydisclosed for clip 64.

Alternatively, a portion of the housing exterior surface 96′ and aportion of the housing interior sidewall surface 86 of the connectorhousing 66 may be constructed of an electrically conductive materialconducive to the joining processes of soldering and/or welding. Theconnector housing 66 is designed such that an electrical connection smade between the terminal pin 18 of the AIMD hermetically sealedfeedthrough 14 and the AIMD active electronic circuit board 106 of theactive implantable medical device 12.

Once again referring to FIG. 7A, the unfiltered or filtered AIMDconnector feedthrough assembly 10 or the feedthrough connector capacitorassembly 20 is positioned within the active implantable medical device12. The housing exterior surface 96′ of the connector housing 66 may beelectrically joined to an electrical connection pad 104 of the AIMDactive electronic circuit board 106 by a laser weld 108′ imparted by ajoining instrument 108. Alternatively, the housing exterior surface 96′may be electrically connected to an electrical connection pad 104 of theAIMD active electronic circuit board 106 by a solder, using a solderingjoining instrument (not shown). In either case, the joining process maybe utilized to join at least a portion of the housing exterior surface96′ to the circuit board electrical connection pad 104.

The electrical connection 107′ may be a laser weld 108′, a solder, athermal-setting conductive adhesive or even a ball grid array typeapproach where, before the connector housings 66 of the terminal pinconnectors 16 are attached to the circuit board electrical connectionpads 104, either a BGA (ball grid array) conductive epoxy or solder bumpwould be applied and then a robot would place the housing exteriorsurface 96′ of the connector housing 68 of all the terminal pinconnectors 16 in place, which, through a bulk reflow operation, thesolder would be reflowed or the conductive epoxy would be cured. If alaser weld 108′ is made, it is contemplated that the circuit boardelectrical connection pad 104 (or alternatively, a circuit board land ora circuit trace) would comprise a metallic pad, such as a Kovar pad,whereby, the laser weld 108′ would include the melting and joining ofthe adjacent materials to form a solid mechanical metallurgical bond anda very low resistance and low impedance electrical connection 107′.Referring once again to FIG. 7A, one will note that there is a goldbraze 46 b that connects and mechanically and hermetically seals theactive terminal pins 18 to the insulator 28. The right-hand sideterminal pin 18 has a gold braze 46 bgnd. In this case, the groundterminal pin 18 gnd is shown gold brazed 48 bgnd directly to themetallic ferrule 26. Alternatively, the ground terminal pin 18 gnd couldbe a laser weld 108′ that directly joins the ground terminal pin 18 gndto the metallic ferrule 26. In the case of a terminal pin laser weld108′ directly to the metallic ferrule 26, the ground terminal pin 18 gndwould need to comprise an oxide-resistant material, or at least becoated with an oxide-resistant material once any oxides that form duringlaser welding are cleaned/removed from the ground terminal pin. Thebrazing or welding process grounds the terminal pin 18 gnd. It is verycommon in pacemaker and ICD applications that the AIMD casing 32 (alsoknown as a can or housing), which essentially comprises two can halves112 and 114, can be used as one of the electrodes. For example, for animplantable cardioverter defibrillator, a defibrillation vector can bebetween the AIMD casing 32 and a distal shocking electrode (not shown),which is placed, for example, in the right ventricle area. To performthis function, the AIMD active electronic circuit board 106 isprogrammed to apply the ICD shock between a grounded pin, such as 18gnd, such that the pulse polarity is between the AIMD casing 32 and thesingle distal electrode. In various applications, the grounded pin maynot extend into the body fluid side of the AIMD 12 as shown, however, incertain neurostimulators or other specialized applications, the groundedpin will extend into the boy fluid side of the AIMD 12.

It is understood to those skilled in the art that the terms AIMD“casing”, “housing” and “can” are synonymous. As used throughout thisspecification, the terms “casing”, “housing” and “can” can be applied tothe overall AIMD hermetically sealed enclosure 32, which may have canhalves 112, 114, or a lid (not shown), and which is generally conductiveand forms an electromagnetic shield (Faraday cage). This is not to beconfused with the housing 66 of the terminal pin connector 16 of thepresent invention. Hence, the use of similar terms “casing”, “housing”and “can” must be taken in context with the structures to which theseterms refer.

Referring to FIGS. 7A and 7B, the circuit board electrical connectionpad 104 could comprise a large circuit board via hole 109, which couldbe designed to accept and receive a round connector housing 66 (notshown). The round connector housing 66 would be mechanically andelectrically attached to the circuit board via hole 109 by one of apress fit, a solder, an electrically conductive adhesive or other commoncircuit board via hole connection material and/or process, includingcrimps, and the like. This embodiment could position the connectorhousing 66 residing in the circuit board via hole 109 perpendicular tothe position illustrated in FIGS. 7A and 7B. As such, the terminal pins18 and 18 gnd could have a 90° bend or other bend angle in order toalign with a housing interior sidewall surface 86 such that the bentterminal pins 18 and 18 gnd could slide along the housing interiorsidewall surface 86 thereby ‘plugging into’ the circuit board connectorhousing 66. Using common multilayer circuit board trace techniques,these circuit board via holes 109 that receive connector housings 66could be staggered in various patterns thereby enabling electricalconnection of high count, high density and/or close pitched feedthroughconductors, including uniquely or other non-traditionally positionedfeedthrough terminal pins 18, 18 gnd, while preserving removability ofcircuit boards for rework or replacement should a circuit board bedeemed defective.

Further regarding circuit board via holes 109, depending on the designof the circuit board, the terminal pin connector, the terminationstructure of terminal pin designs, or combinations thereof, terminalpins 18 and 18 gnd may not require a bending operation. For example,FIG. 19 illustrates an embodiment of a feedthrough capacitor connectorassembly 20 having circuit board via hole 109, within which a two-partpin resides. The two-part pin of FIG. 19 comprises a first pincomprising a terminal pin 18 partially residing in the insulator bore ofthe feedthrough conductive pathway, in this case, extending from thebody fluid side of the insulator 28, and a second pin comprising Aterminal pin 18′ having a compliant termination structure 81, the secondpin partially residing in the same insulator bore of the feedthroughconductive pathway, however, in this case, extending from the deviceside of the insulator 28. Both terminal pin 18 and terminal pin 18′residing within the same insulator bore of the feedthrough conductivepathway of the AIMD hermetically sealed feedthrough form the two-partpin. The compliant termination structure 81 of the terminal pin 18′extending from the device side insulator 28 is shown passing through theactive capacitor dielectric bore of the externally grounded feedthroughcapacitor 24′, and then directly inserted through circuit board via hole109 in-line with the longitudinal axis of the two-part pin, that is,terminal pins 18 and 18′. FIG. 19 illustrates terminal pin 18′ directlyelectrically connected to the circuit board without a bending anglewhich can be a 90° or some other bending angle.

FIG. 7C is taken from section 7C-7C of FIGS. 7A and 7B. Illustrated is aterminal pin 18 bent to an angle (radiused R), which could be a radiused90° right angle. A radiused bend is preferred for better shock andvibration resistance. Position arrow P illustrates how the bent terminalpin 18 would be inserted into the clip through-bore of connector housing66 residing in the circuit board via hole 109 of the electricalconnection pad 104. As previously described, the connector housing 66would be attached to make an electrical connection 107′. In this case,the connector housing 66 is round along with a round alignment feature75 comprising an alignment flange 75′ at the proximal housing end 80 foraccepting and receiving a terminal pin 18. Prong(s) 70 are shownresiding within the connector housing 66. It is contemplated,particularly if the circuit board is thick enough, that the prong(s) 70could instead alternatively reside on a terminal pin 18 and not withinthe connector housing 66. Terminal pins having compliant terminationfeatures could thereby plug directly into a connector housing 66 thatare absent prongs. Such embodiments are illustrated in FIGS. 19, 19Athrough 19D, 20, and 21.

Referring once again to FIG. 7C, one will appreciate that the electricalelectrical connection 107′ can comprise an electrically conductivecircuit board via hole 109, which typically comprises circuit board viahole electrically conductive plating, eyelets and the like. In otherwords, connector housing 66 could be press-fitted into the circuit boardvia hole 109 of the electrical connection pad 104. The position arrow Pillustrates how the terminal pin 18 is inserted into the clipthrough-bore to the prong(s) 70. The position arrow P could alsoalternatively be reversed such that the clip through-bore with theprong(s) 70 of the connector housing 66 of the AIMD active electroniccircuit board 106 is aligned with a bent terminal pin distal end 62 andthen a push force is applied so that the circuit board can be pushedonto the terminal pin 18.

The AIMD feedthrough connector assembly 10 or feedthrough capacitorconnector assembly 20 may be designed for use with a “clam shell” styleAIMD casing 32. A “clam shell” type AIMD casing 32 comprises two casinghalves 112, 114 that are essentially mirror images of each other,meaning that the two casing halves appear almost identical, but arereversed in the direction perpendicular to the mirror surface. The twocasing halves 112, 114 are brought together to form an AIMD casing 32.In embodiments illustrated in FIGS. 8 and 9, the AIMD feedthroughconnector assembly 10 (or feedthrough capacitor connector assembly 20not shown) is positioned within a casing inlet 110 of a first casinghalf 112 of the AIMD casing 32. The flange 30 of the ferrule 26 istypically welded to the casing half within the casing inlet 110. Theterminal pin connectors 16, attached to their respective terminal pins18 and 18 gnd, are then positioned on the circuit board electricalconnection pads 104 of the AIMD active electronic circuit board 106 andelectrical connection 107′ is made.

Referring to FIG. 7B, in an embodiment, the terminal pin connector 16 ispositioned and attached to the circuit board electrical connection pads104 of an AIMD active electronic circuit board 106 by an electricalconnection material 107 (not shown), such as by soldering,thermal-setting conductive adhesives, brazing, welding or the like, toform electrical connection 107′. After the terminal pin connector 16 hasbeen mechanically and electrically attached to the circuit boardelectrical connection pad 104, the hermetic seal assembly, includingterminal pins 18 and 18 gnd may be positioned, wherein the terminal pinsare inserted into their respective terminal pin connector 16. Once theterminal pins 18 and 18 gnd are correctly positioned, the flange 30 ofthe ferrule 26 may be tack welded 119 to the first casing half 112. Thistack weld 119 positions and holds the ferrule 26 to the casing half 112.At this time, final visual and electrical inspections are made, andthen, if inspection is passed, a second casing half 114 can be placed sothat a continuous laser weld 116 is made between the casing halves andall around the ferrule 26 such that the entire AIMD casing 32 ismechanically and hermetically sealed. There is typically a step beforethe final hermetic seal is made involving vacuum baking of the AIMDcasing 32 and back-filling the AIMD casing with an inert gas optionallyhaving a tracer gas such as helium or argon. This step is well known inthe prior art and will not be further described herein. Shown in FIG. 7Bis an AIMD hermetically sealed feedthrough 14 that has terminal pins 18hermetically sealed to an insulator 28 and a ground terminal pin 18 gndextending through the ferrule 26 of the AIMD hermetically sealedfeedthrough 14 to a body fluid side and a device side. After the AIMDcasing 32 is hermetically sealed by joining casing halves 112, 114, thedevice side is defined herein as inside the AIMD casing 32 and the bodyfluid side is defined herein as outside the AIMD casing 32.

Referring once again to FIG. 7A, one can see that after the terminalpins 18, 18 gnd have been inserted into the terminal pin connectors 16,similarly to FIG. 7B above, the flange 30 of the ferrule 26 may be tackwelded 119 to the first casing half 112, positioning and holding theferrule 26 to the casing half 112, such that all of the circuit boardconnections can be made. The AIMD active electronic circuit board 106 isthen tested, and if testing is passed, then the second casing half 114can be positioned for laser welding. A continuous laser weld 116, 118′is made from the body fluid side of the AIMD casing 32. It is notedthat, while FIG. 7A shows the AIMD components within the AIMD casing 32,once the second casing half 114 is laser welded to the first casing half112 and to the ferrule 26 of the AIMD hermetically sealed feedthrough14, none of the components inside the AIMD casing 32 would be visible.The laser welds 116, 116′, forms a continuous seam that hermeticallyseals the two can halves 112, 114 and 116′ the entire perimeter orcircumference of the ferrule 26 of the AIMD. The continuous seam forminga complete hermetic seal thereby protects all of the AIMD electroniccircuits and other components residing inside the AIMD casing 32, whilealso forming a Faraday shield (also called a Faraday cage), which is aneffective electromagnetic shield against high frequency undesirableelectromagnetic interference (EMI).

Referring now to FIG. 7C, illustrated is an embodiment comprising analternative connector housing 66 to the connector housing having planarsurfaces shown in 7C-7C of FIGS. 7A and 7B. In this case, the connectorhousing 66 is shown inserted into a circuit board via hole 109 insteadof having a planar surface attached to an electrical connection pad 104as taught in FIGS. 7A and 7B. The circuit board via hole 109 of FIG. 7Cis further associated with round electrical connection pad 104′. It iscontemplated that the electrical connection pad 104′, which could alsobe square or any other geometry. A mechanical and electrical connection107 is shown, which could comprise an electrical connection material 107such as a solder, a thermal-setting conductive adhesive or the like. Theelevated alignment feature 75 at the proximal housing end 80 of theconnector housing 66 is an alignment flange 75′ and is only shownelevated so that the mechanical and electrical connection 107′ isvisible in order to appreciate the connection joining structure. Inreality, the alignment feature 75 is actually set down against theconnection joining structure, which may comprise one of a press-fit, asolder or a thermal-setting conductive adhesive. When the alignmentfeature 75 is set down against the connection joining structure, thealignment flange 75′ of the alignment feature will mimic a filet or arounding edge, which exists but is not actually shown in FIG. 7C.Further regarding the proximal housing end 80, prongs 70 areillustrated. It is contemplated, however, that any of the elasticallyresilient conductive structures of the present application may be withinthe connector housing 66 instead of prongs 70. FIG. 7C illustrates aterminal pin 18 comprising a bend, the bend having a radius R. It iscontemplated that the bend of the terminal pin 18 can be a radiused 90°bend or another suitable radiused angle such that the AIMD activeelectronic circuit board 106 and the terminal pin 18 can be removablyattached. For example, a downward push force may be applied to the AIMDactive electronic circuit board 106, while an upward push force can beapplied to the terminal pin distal end 62 of the terminal pin 18 so thatthe terminal pin 18 is inserted into the connector housing 66 andgrasped by the prongs 70 thus being mechanically and electricallycaptured by the prongs 70. If testing indicates that the AIMD activeelectronic circuit board 106 is defective, applying pull force oppositethe insertion push force allows removal of the defective circuit boardfor either replacement or rework. The embodiment illustrated in FIG. 7C,has enhanced resistance to shock and vibration, and is also resilient tothermal forces that may be introduced by mismatched rates of thermalexpansion due to the various different materials of construction withinAIMD components or subassemblies, including the AIMD active electroniccircuit board 106 and the AIMD casing 32. The radius R can be customizedto accommodate various lead extensions, lengths or orientations.Moreover, the radius allows for flexure during perturbations includingthermal expansion mismatch movement, shock, vibration and eveninsertion/retraction forces. Referring once again to FIG. 7C, one willsee that the connector housing 66 is round instead of rectangular orsquare, as illustrated in other embodiments herein, and has an alignmentfeature 75 and the alignment flange 75′, both of which are also round.It is contemplated that other shapes could be used for the connectorhousing 66, alignment feature 75 and/or alignment flange 75′ includingsquare, rectangular, hexagonal, elliptical or the like. FIG. 7C alsoshows the terminal pin distal end 62 of the bent terminal pin 18 beingpushed into the connector 66 in the direction indicated by the arrowrepresenting a push force P. Radius R may be a single radius, as shown,or may comprise multiple radii all along the length of terminal pin 18,which extends from the device side of the insulator (not shown) Into theAIMD casing 32. In other words, the terminal pin 18 may be bent invarious accommodating configurations in order for the terminal pindistal end 62 to engage the prong 70.

FIG. 8 illustrates a cutaway view of an AIMD 12 showing the terminal pinconnector 16, of the present invention, mechanically and electricallyattached to the AIMD active electronic circuit board 106. The AIMDhermetically sealed feedthrough 14, 10 is shown with the correspondingterminal pins 18, 18 gnd plugged into the terminal pin connector 16.There is also an internally grounded feedthrough capacitor 24′ that isdisposed on the inside of the AIMD casing 32. In FIG. 8, the internallygrounded feedthrough capacitor 24′ does not have an external, perimeteror outer metallization layer; instead, the internally groundedfeedthrough capacitor 24′ is grounded to the terminal pins 18 gndresiding at both ends of the ground terminal pins. These ground terminalpins 18 gnd are either gold brazed or laser welded directly to theferrule 26 and provide a solid mechanical and low impedance RF groundfor the internally grounded feedthrough capacitor 24′. This is aconvenient way of providing grounds to the AIMD active electroniccircuit board 106. In FIG. 8, there are five active terminal pins 18 andthe two ground terminal pins each labeled 18 gnd.

Referring once again to FIG. 8, illustrated is one casing half 112 ofthe AIMD casing 32, which can have a multiplicity of shapes, of whichonly one exemplary shape of many shape possibilities (includingcustomized shapes) s shown. Illustrated is a ferrule 26 fitted into anopening in an AIMD casing 32 such that a laser weld can be madehermetically sealing the AIMD pulse generator. It is noted that theferrule 26 in FIG. 8 may comprise an H-flange 30 as shown in FIGS. 3, 3Band 3C, which captures the casing half 112, or alternatively, ferrule 26may comprise an L-flange, an F-flange, an indent flange or a barrelflange, including the flange configuration shown in FIG. 8. It will beappreciated that the ferrule 26 of FIG. 8 is only a non-limitingexemplary configuration, thus ferrule and AIMD casing configurations mayvary.

FIG. 9 illustrates perspective view of a first casing half 112 withvarious components internal to an AIMD prior to hermeticaly sealing asecond casing half thereby forming AMID casing 32 of an AIMD 12. Shownis a battery 130, which can be either a primary or a secondary battery.For example, in the case that the AIMD 12 is a cardiac pacemaker, thebattery 130 could be a primary battery, while, in the case that the AIMD12 is a neurostimulator, the battery 130 could be a secondary battery orrechargeable battery. The main AIMD active electronic circuit board 106is also shown along with at least one microprocessor 131 and variousother circuit board components 133. The AIMD active electronic circuitboard 106 has a plurality of terminal pin connector housings 16 thathave also been mechanically and electrically attached to the AIMD activeelectronic circuit board 106 and, importantly, to its circuit boardinputs and outputs. Circuit boards contain the circuits that provide,for example, pacing pulses to simulate the natural biological signals ofthe heart, sending pacing pulses from the pacemaker circuit to aterminal pin, and then from the terminal pin to the distal electrodes ofan implanted lead in order to treat cardiac arrhythmias (problems with arate or rhythm of a heartbeat). Circuit boards can also comprisecircuits that can sense biological signals received by sense amplifierswithin a circuit of a microprocessor 131. Circuit boards may alsocomprise circuits for telemetry to which one or more RF telemetry pinsare connected. In general, RF telemetry antennas would be included in anAIMD header block area (not shown), and the RF telemetry signal wouldpass from the RF telemetry antenna to the one or more RF telemetry pins,and then from the RF telemetry pin to the microprocessor of the circuitboard. Accordingly, an AIMD is thereby enabled to sense, process andadjust a pacing therapy in accordance with specific patient needs and/orto communicate data.

Referring once again to FIG. 9, one can see that the AIMD activeelectronic circuit board 106 has been ‘plugged in’ and connected to thehermetic seal terminal pins 18 of the AIMD hermetically seal feedthrough14. The circuit board is also shown connected to the battery 130. As hasbeen previously disclosed, there may be an internally groundedfeedthrough capacitor 24′ attached to the AIMD hermetically sealfeedthrough 14 (not shown), or instead of a feedthrough capacitor, anEMI filter circuit board 106′ (not shown) comprising one of an MLCC, anX2Y attenuator, a flat-thru capacitor or combinations thereof can beused.

FIG. 9A illustrates embodiments of terminal pin connectors 16, 16′ and16″ for use with an AIMD hermetically seal feedthrough 14 having astaggered terminal pin 18 configuration. It is understood by one skilledin the art that terminal pin connectors may be shaped, positioned,oriented, or otherwise mounted to accommodate any terminal pinconfiguration of an AIMD hermetically sealed feedthrough 14, includingone of a staggered terminal pin configuration, a dual in-line terminalpin configuration, or a custom terminal pin configuration. Referringonce again to the terminal pin connectors of FIG. 9A, terminal pinconnector 16 is configured as previously disclosed in the presentapplication. The embodiment of terminal pin connector 16′ providesheight to the terminal pin connector, thereby having an elevatedinsertion though-bore with respect to that of the terminal pin connector16 so that the terminal pin connector 16′ suitably aligns with arespective staggered terminal pin. To save weight, terminal pinconnector 16′ may comprise an optional cutout 188 as illustrated. Theembodiment of terminal pin connector 16″ essentially embodies the shapeof the terminal pin connector 16′, except that the terminal pinconnector 16″ comprises a flat cutoff that is attached to a conductivespacer block 190. The conductive spacer block 190 may be electricallyattached to at least one of the circuit board electrical connection pad104 as shown, a circuit board trace 105 (not shown) or a circuit boardland (not shown). It is noted that the alignment feature 75 of theterminal pin connectors 16 of FIG. 9A are disposed so that the alignmentfeature 75 overhangs the edge of the AIMD active electronic circuitboard 106 to facilitate a flat attachment for proper bonding andelectrical connection 107′ to the circuit board electrical connectionpad 104. The circuit board electrical connection pad 104 area issufficiently large to allow robotic dispensing of solder dots, ball gridarrays and the like.

FIG. 9B illustrates an embodiment of a terminal pin connectors 16″ and16″ ″ suitable for a dual in-line terminal pin 18 configuration. In thiscase, the terminal pins 18 are vertically aligned one above the other.The hermetically sealed feedthrough 14 of FIG. 98 comprises eighthermetically sealed terminal pins 18 extending through the insulator 28of the AIMD hermetically sealed feedthrough 14 from a body fluid side toa device side. After the AIMD casing 32 is hermetically sealed byjoining can halves 112, 114, the device side of the insulator 28 isinside the AIMD casing 32 and the body fluid side is outside the AIMDcasing 32. The terminal pin connectors illustrated in FIG. 9B arestaggered to accommodate insertion of each terminal pin of the dualin-line terminal pin configuration into its respective terminal pinconnector. The terminal pin connectors can be attached either using aBGA dot or a thermal-setting conductive adhesive dot or an edgeelectrical connection. In the embodiment of FIG. 9B, terminal pinconnector 16″ ″ accommodates the shorter terminal pins 18′, whileterminal pin connectors 16″ accommodates the longer terminal pins 18.The short and long terminal pin configuration ensures that only terminalpin 18′ are inserted into terminal pin connector 16″ ″ and only terminalpin 18 are inserted into terminal pin connector 16″. Additionally, theheight of terminal pin connectors 16″ ″ is defined such that terminalpins 18 will not make contact to terminal pin connectors 16″ ″. Terminalpin connectors 16″ have a separate open spacer block 190′, however it iscontemplated that terminal pin connectors 16″ can comprise a solidspacer block. Additionally, the terminal pin connectors 16″ may also bea one-piece structure instead of a multi-piece structure as shown.Multi-piece terminal pin connector structures will have an electricalconnection 107′ as shown. The spacer block 190′ is attached to circuitboard electrical connection pads 104 (or alternately to circuit tracesor circuit board lands not shown) as previously described for terminalpin connector 16. The through-bore of the terminal pin connector 16″ isspatially aligned to line up along the axis of the length of theterminal pins 18 of the hermetic feedthrough seal 14 so that insertionof the terminal pin distal end can be made. Importantly, duringinsertion of the AIMD active electronic circuit board 106, terminal pins18 and 18′ should be assembled such that, when the AIMD activeelectronic circuit board 106 is attached to the terminal pins 18 and18′, the terminal pins will not substantially deflect or bend. Dependingon the terminal pin material of construction, either the terminal pinscan have an applied force such as by a fixture to prevent deflectionand/or bending during the insertion process, or the terminal pins mayhave a specified material composition and/or properties, as terminal pinmaterials can then be specifically chosen based on a material's flexuralstrength, which is the amount of bending force a material can withstandwithout being substantially deflection or compromisingly bent.

FIG. 10 illustrates an active implantable medical device 12 known as animplantable cardioverter defibrillator (ICD). An ICD has a hermeticallysealed metallic AIMD casing 32 generally of titanium. An ICD alsocomprises an AIMD header block 118 into which therapy delivery leadwiresrouted to the heart are plugged as shown. Illustrated are ISOinternational standard industry lead connectors IS-1 and DF-1. An IS-1lead connector is a low-voltage pacing/sensor lead connector. A DF-1lead connector is a high-voltage shock lead connector. A first leadwireis shown routed to the right ventricle of the heart, which, in this casehas one IS-1 lead connector and two DF-1 lead connectors, the three leadconnectors joined together at a yoke integrating these lead connectorsinto the single lead body illustrated. The first leadwire comprises acoil electrode at the superior Vena Cava (SVC), and both a coilelectrode and a ring electrode in the right ventricle. The secondleadwire comprising a ring electrode is shown routed to the rightatrium. This embodiment represents a standard dual chamber pacing systemwith defibrillation capabilities. It is understood that a variety oftherapy delivery leadwire configurations are possible as are a multitudeof locations that electrodes can be routed transvenously to contacteither the myocardium of the heart or that floats in the heart bloodpool.

Regarding the AIMD header block 118, header blocks are generally thelast thing to be placed on an AIMD and can be cast or molded directly tothe AIMD 12 or, alternatively, pre-formed or pre-molded and thenattached to the AIMD, either by biocompatible mechanical fastener(s)and/or adhesive(s). AIMD header blocks are typically made using arelatively hard, insulative polymer, such as, but not limited toTecothane®. The AIMD header block 118, as FIG. 10 illustrates, usuallyhas a thickness approximating the thickness of the AIMD casing 12 andincludes a surface that conforms to the mating surface of the AIMDcasing. AIMD header blocks, in their own right, are very complicated andcomprise many components. Hence, there is a need for AIMD header blocksthat easily plug into an AIMD. The header blocks of present day AIMDsare generally securely affixed to an AIMD casing such that the AIMDheader block is not removable without causing damage to the AIMD; hence,if an AIMD header block is deemed defective after the AIMD header blockis affixed to an AIMD casing, replacement or rework of the defectiveAIMD header block is not possible, and so the entire AIMD is rejectedand scrapped.

The Lim Patent Publication 2017/0266451 teaches a plug-in header block,the contents of which are fully incorporated herein by this reference.However, the header block of Lim includes a conductor assembly, afeedthrough coupled to the conductor assembly, and a polymer header thatwas injection molded about the conductor assembly and at least a portionof the feedthrough. The terminal pins of the feedthrough of theconductor assembly are plugged into electrical receptacles residing inthe AIMD casing, and then the AIMD casing is welded to the plugged infeedthrough. One problem with Um's approach is that the welding processcreates considerable heat, which could be damaging to the polymermaterial forming the header. Polymer materials easily carburize at hightemperatures, which could cause deleterious electrically conductiveareas in an otherwise insulative header block. Another problem withLim's approach is that the feedthrough is subjected to three thermalperturbations in this order: (1) each terminal pin of the feedthrough issubjected to a joining temperature when the terminal pins of thefeedthrough are welded to their corresponding electrically conductivecomponent; (2) the feedthrough is additionally subjected to theinjection molding temperatures; and (3) the feedthrough is againsubjected to welding temperatures when the AIMD casing is welded to theplugged in feedthrough. Once the feedthrough is injection molded,hermeticity testing of the feedthrough is likely not doable. Moreimportantly, since the feedthrough was incorporated into the header bythe injection molding process, there is no way to determine if thefeedthrough is still hermetic. Historically, feedthroughs have at timescaused device recalls due to loss of feedthrough hermeticity.

FIGS. 11, 12 and 13 of the present application are related to FIGS. 3,4A and 4B of Lim, which are a representative header (FIG. 3) withinwhich resides various electrically conductive components (FIGS. 4A and4B). Illustrated in FIGS. 4A and 4B of Lim are the followingelectrically conductive components: an antenna (48), an RF anchor tab(50), and RF pin tabs (52) and (60). It is noted that the elementnumbers in parenthesis refer to those element numbers of the Limpublication. Given the Lim problems discussed above, the inventorsresolve the issues associated with the Lim header connector assembly byproviding an embodiment of a removable AIMD header block that does notrequire a feedthrough. Instead, the removable AIMD header block of thepresent application attaches to the terminal pins of present day AIMDswithout having to change existing AIMD pulse generator manufacturing,inspection or quality testing processes. Shown in FIGS. 12 and 13 of thepresent application are electrical conductors 122 to which areelectrically connected to the terminal pin connectors 16 of the presentinvention. The electrical conductors 122, which are present within theheader residing on the body fluid side of the AIMD 12, are shown laserwelded 124 to the terminal pin connectors 18.

Referring once again to FIGS. 12 and 13, since the electricallyconductive components will be exposed to body fluids when implanted, theelectrically conductive components of the AIMD header block 118comprises biocompatible, non-toxic and biostable materials ofconstruction. For example, the electrical conductors 122, the terminalpin connectors 16, and the other components shown in FIGS. 12 and 13 maycomprise any of the biocompatible and biostable materials, as previouslydescribed in addition to stainless steel, particularly 316L stainlesssteel, MP35N®, Nitinol, cobalt chromium alloys, titanium, niobium,tantalum gold, platinum and palladium. Also shown are ports withcircumferential springs 128 such as made by BalSeal®, which are wellknown in the art, and cavities that are optionally present for setscrews, fasteners, or other fastening/attachment medium.

FIG. 13 is very similar to FIG. 12, except that it has been rotated sothat one can more clearly see the terminal pin connectors 16 of thepresent invention. One will appreciate that the connector housing 66, asillustrated, could be staggered to align with either a staggeredterminal pin hermetic seal or a dual in-line terminal pin hermetic seal.This would mean that the conductors that they are attached to are alsostaggered.

Referring once again to FIGS. 12 and 13, it is contemplated that theterminal pin connectors 16, which are attached to the electricalconductors 122, could instead comprise any of the compliant terminationstructures 70′ disclosed herein, even pin compliant terminationstructures 81, 81′, 81″, 81′″, and 81″ as illustrated in FIGS. 19through 19D, and clip 64/prong 70 type pin compliant terminationstructures such as illustrated in FIGS. 20 and 21. Furthermore, addingany of the pin compliant termination structures of the presentapplication to the electrical conductors 122 of FIGS. 12 and 13 enablesfeedthroughs comprising one or more cavities 180, as illustrated inexemplary FIGS. 22 through 24. Likewise, adding any of the pin complianttermination structures of the present application to the electricalconductors 122 of FIGS. 12 and 13 further enables feedthroughs havingterminal pins attached to only a connector housing 66 (the connectorhousing is entirely absent any clip, prongs or compliant terminationstructure), see, for example, the connector housings of FIGS. 20, 21, 25and 26, to receive such pin compliant terminations.

Referring once again to circumferential springs, while circumferentialsprings 128 (often called BalSeal® springs) are used in prior art AIMDheader blocks 118 for insertion of implanted lead distal ends, suchcircumferential springs being biocompatible, biostable and non-toxic, itis contemplated, in accordance with the present invention, that thecircumferential springs can be used in terminal pin connectors 16 or incompliant termination structures 70′ as taught herein. Further regardingBalSeal® springs, example header block spring concepts are disclosed inU.S. Pat. Nos. 7,195,523; 7,822,477; 8,096,838; and 8,437,855 allassigned to BalSeal, which, the contents of which are fully incorporatedherein by these references. Such BalSeal header block circumferentialsprings are termed in-line garter springs (element 44 in U.S. Pat. No.7,195,523), leaf springs (element 50 in U.S. Pat. No. 7,822,477), springcontact elements (element 54 in U.S. Pat. No. 8,096,838) and canted coilsprings (element 28 of U.S. Pat. No. 8,437,855). It is noted that allelement numbers shown in parenthesis are taken from the BalSeal patents.The BalSeal springs are shown spaced in line in slots in the headerblock in order to receive and electrically connect to a plurality ofelectrically conductive rings associated with the proximal plug of animplantable therapy delivery leadwire. These electrically conductiverings are placed at the proximal end of male therapy delivery leadwireconnectors typically of AIMDs like cardiac pacemakers, implantablecardioverter defibrillators, neurostimulators and the like. Bydefinition, the rings must be insulated from one another or AIMDfunctions would be shorted out. Accordingly, all of these in-line springtypes are held within an insulative housing (58) as illustrated in theBalSeal '523 patent. The key distinction is illustrated in FIG. 3 of the'523 patent, in that, the leadwire (70) of the BalSeal feedthrough,which would be considered terminal pin 18 of the present application, iselectrically and mechanically attached to an outside ring (40), in whicha garter spring (44) resides. In no case, in the '523 patent, is ittaught or suggested that the leadwire (70) of the '523 could be pluggedinto the center hole space (12) of the garter spring (44) thereby makinga direct electrical connection to the garter spring (44). In summary,there are several key differences between the present invention and theBalSeal '523 invention, including the fact that the BalSeal's gartersprings (44) are all spatially in-line and are all contained with anoverall insulating body (58) to prevent the garter springs from shortingout to each other. Moreover, all of the leadwires (70) of thefeedthrough are taught being attached to the outside ring (40). Thefeedthrough leadwires (70) are never shown plugged into the centerthrough-bore of the garter spring (44). In contrast, the presentapplication discloses that, whether the contact member is a spring, aprong or other elastically resilient conductive structure, andregardless of whether the contact member resides within a header block,a circuit board or the feedthrough itself, terminal pins are insertedinto a central through-bore to connect to the inside of a conductivestructure such as a connector housing 66, a terminal pin connector 16 ora cavity 152 within a co-sintered conductive paste-filled via 146.Moreover, the connector housing 66 and/or terminal pin connector 16 ofthe present invention, are not only electrically conductive, but arealso designed for robotic placement on an AIMD active circuit board 106or an EMI filter circuit board 106′, which is not taught by any of theBalSeal patents. Such connector housings 66 and/or terminal pinconnectors 16 of the present application are populated adjacently (suchas, but not limited to, dual in-line as illustrated in FIG. 9B), oradjacent to each other in varying positions in order to receive terminalpins 18 of an AIMD hermetically sealed feedthrough 14 of an AIMD 12regardless of the number of terminal pins or the design of thefeedthrough. In this way, each terminal pin 18 is electrically connectedto electrical conductor 122 of the AIMD header block 118 and the AIMDinternal electronic circuitry by plugging in so that the connectorhousing 66, which is housed in a conductive structure of the AIMD headerblock 118 or in/on the circuit board, the conductive structurecompleting the circuit path by electrically connecting to a circuitboard land, a circuit board pad, a circuit trace or the like andultimately, through the terminal pins 18 and the attached AIMD headerblock 118, to the electrodes of the therapy delivery leads of the AIMD12.

BalSeal U.S. Pat. No. 7,822,477 is similar to the '523, except that, inthe '477 patent, instead of a garter spring (44 of the '523, also knownas Gerber springs), a leaf spring (50) of a leaf spring contact element(28) is illustrated. For example, in FIGS. 1 through 4 of the '477patent, shown is a therapy delivery lead termed a medical lead cable(12) having a male plug proximal end (19) with conductive ringelectrical terminals (16) within which the leaf spring (50) resides.Such leaf springs are spaced along the length of the plug in insulativerelationship with each other. As the proximal end of the medical leadcable is inserted into the housing (26) of the conductive ring of the'477 patent, the proximal end is inserted and compressed by the leafspring (50) such that electrical contact is made. There is also anelectrical circuit connection, in this case, lead (36), which isconnectable to a feedthrough wire (not labelled) of an AIMD feedthrough(see '477 FIG. 11 element 36). The AIMD feedthrough of the '477 patentis inferred as there is no description of the hermetic feedthrough muchless of an AIMD active circuit board in the '477 patent specification.Similar to the '523, these leaf springs are in-line and also must beinsulated from each other by seal rings (24) or the leaf springs wouldshort out to each other. There is no teaching or suggestion that theleaf springs could be separate individual electrical contacts capable ofbeing populated on an AIMD active electronic circuit board 106 or an EMIfilter circuit board 106′. Additionally, there is no teaching orsuggestion that would indicate the leaf springs could be separated outand spaced apart in parallel and then individually connected to circuitboard electrical connection pads 104, circuit traces 105 or generally toAIMD circuits.

The other FIGS. 5A through 11 of the '477 are very similar to FIGS. 1through 4 illustrating a number of embodiments of leaf springs, leaffingers, and prongs. All these embodiments are ultimately connected to alead (36) extending from the base (52) of the contact element (28),which becomes part of the header block wiring and is routed to an inputor output of an electrical circuit of the device. Similar to the '523patent, the '477 patent also has no teaching or suggestion of the AIMDfeedthrough terminal pin itself (terminal pin 18 of the presentinvention) being inserted into a through-bore of the leaf springs inorder to connect to the inside of a conductive structure as taught bythe present application. In addition, and in contrast to the teachingsof the present application, the leaf springs of the '477 are all in-lineand individually insulated to receive the proximal plug contact rings ofmulti-inductor implantable therapy delivery leadwires, providing onlythe lead (36) for connection between the header block and pulsegenerator of an AIMD.

The BalSeal '838 patent also teaches in-line header block spring contactelements to make contact with the rings of a proximal implantable leadplug. Referring to FIG. 3B of the BalSeal '838 patent, illustrated is aco-formed insulator 26 that electrically isolates the in-line electricalcontacts from each other. Similarly to the '523 and '477 patents, thereis no teaching or suggestion in the '838 patent that these springcontact elements could be separated out or that the AIMD feedthroughterminal pin itself could be inserted into a through-bore of a springcontact element in order to connect to the inside of an AIMD as taughtby the present application, or that even the methods of insulationdisclosed in the '838 would even be useful to the invention(s) of thepresent application.

The BalSeal '855 patent also teaches more of the same, namely in-linecoaxial springs insulated from one another. There is no teaching orsuggestion that such coaxial springs could be separated individually andpopulated on an AIMD active electronic circuit board 106 or an EMIfilter board 106′ as taught by the present application. There is noteaching or suggestion that would indicate separated individual coaxialsprings could be spaced apart in parallel so that individual connectioncould even be made to circuit board electrical connection pads 104,traces 105 or circuits. There is also no teaching or suggestion that anAIMD feedthrough terminal pin itself could be inserted into athrough-bore of a coaxial spring in order to connect to the inside of anAIMD as taught by the present application.

In summary, the present application teaches implantable terminal pins 18of an AIMD hermetically sealed feedthrough 14 that can be inserted intonovel terminal pin connectors 16, which may comprise complianttermination structures, including circumferential springs, therebyenabling a removable electrical connection so that replacement or reworkof one of an AIMD active electronic circuit board 106, an EMI filterboard 106″, an AIMD header block 118, or combinations thereof can bedone. Additionally, the AIMD active electronic circuit board 106, theEMI filter board 106″, the AIMD header block 118, or combinationsthereof can be further configured for optional removability so thatdecisions regarding the removability of any one or more of thesecomponents can be made.

For more variations of AIMD header blocks 118, one is referred to U.S.Pat. Nos. 8,437,855; 8,103,348; 8,065,009; 7,822,477; 7,751,893;7,630,768; 7,295,123; 7,167,749; and 7,068,081, the contents of whichare fully incorporated herein by these references. Additionally, U.S.Pat. No. 10,376,688 discloses neurostimulator interconnection apparatusand is also fully incorporated herein by this reference.

FIG. 14 illustrates an AIMD 12, which as previously disclosed, can be avariety of active implantable medical devices. The AIMD shownillustrates a metallic first casing half 112, which has been laser tackwelded to the ferrule 28 of the AIMD hermetically sealed feedthrough 14.Only a first casing half 112 is illustrated so that the internalcomponents of the AIMD 12 are visible. It is understood that a secondcasing half 114 is mated to the first casing half, which is then laserwelded forming a continuous weld seam around the perimeters of theferrule 26 and the first and second case halves, thereby forming amechanical and hermetically sealed AIMD casing 32. Accordingly, FIG. 14illustrates some internal components inside a mechanically andhermetically sealed AIMD casing, for example, an AIMD battery, an AIMDcircuit board and exemplary terminal pin connectors 16 of the presentapplication. In this embodiment, a push force is applied to the AIMDactive electronic circuit board 106 such that each terminal pin 18 isinserted into its respective terminal pin connector 16.

Similarly, while it is understood that various components (see FIGS.11-13) exist within the AIMD header block 118, for simplicity, the AIMDheader block 118 only illustrates the formed insulating structure 120,an opening 183, and various holes such as hole 182 into which a threadedfastener 186 eventually secures the header block to a header fixationblock 184. Traditionally, the opening 183 of the header block 118 isused to connect the terminal pins 18 extending from the body fluid sideof the AIMD pulse generator to the electrical conductors (not shown)residing within the header block. Referring again to FIG. 14, the AIMDheader block 118 of the present application, depending on the design ofthe AIMD hermetically sealed feedthrough 14, can comprise any of theterminal pin connector 16 embodiments of the present application. A pushforce is then applied to AIMD header block 118 such that the terminalpins 18 are each inserted into its respective terminal pin connector 16.The opening 183 now becomes an optional feature, as the formedinsulating structure 120 does not require the opening 183 to connect theheader to the terminal pins of the AIMD pulse generator. However, if theopening 183 is present, the opening can be closed by applying and curinga relatively hard, suitable insulative polymer as traditionally done. Itis contemplated that a feedthrough capacitor 24, 24′, or 24″ (not shown)or an EMI filter circuit board 106′ may be installed on or near the AIMDhermetically sealed feedthrough 14 of FIG. 14 on the device side betweenthe terminal pins 18 and the terminal pin connectors 16. Alternately,the feedthrough capacitor 24, 24′, or 24″ (not shown) may be installedon the body fluid side of the AIMD hermetically sealed feedthrough 14,instead of on the device side. Once an AIMD header block 118 is pluggedin place on the AIMD casing 32 and the terminal pins 18 of the AIMDhermetically sealed feedthrough 14 are inserted, t is important that theAIMD header block 118 be mechanically affixed in place so that the AIMDheader block 118 does not come loose or fall off the AIMD pulsegenerator. This can be done by one of: using the threaded fastener 186and the header fixation block 184, adding an adhesive (not shown), usingconnector features as indicated in FIG. 14A, and combinations thereof.

Referring now to FIG. 14A, one can see that the prongs 70 are capturedin a notch 61 of the terminal pin 18. The notch of FIG. 14A illustratescorners that essentially have right angles. As such, the notch 61enables the prongs 70 to more firmly grip the terminal pin 18. Such afirmer grip of the terminal pin 18 may require increased pull force of aterminal pin connector 16 for removal from the terminal pin 18. In thecase of required increased pun force, removal of the terminal pinconnector 16 can be facilitated by use of a tool, such as a slender toolinserted into and along the alignment flange 75′ into the connectorhousing through-bore 78 of the connector housing 66 to push prong 70outwardly from the terminal pin 18 thereby opening the prong 70 andfacilitating release from the terminal pin 18. A tool is notillustrated, however, could be a structure similar to a dental pick orother a slender probe that could slide along the terminal pin 18 betweenthe terminal pin and the prong 70, thereby opening the prong 70.

An alternative for releasing the prong 70 from the notch 61 of theterminal pin 18 of FIG. 14A would be to manufacture the prong of ashape-memory alloys such as, but not limited to: Nitinol (anickel-titanium alloy: TiNi), or a Nitinol-based alloy, a copper-basedshape-memory alloy (such as copper-aluminum-nickel alloy: Cu-AI-NI orcopper-zinc-aluminum alloy: Cu—Zn Al) or an iron-based shape-memoryalloy (using iron alloyed with, for example, zinc, copper, and gold oran iron-manganese-silicon alloy: Fe—Mn—Si). Shape-memory alloys arestable and provide practicality of the terminal pin connectors 16 of thepresent application in that such shape-memory alloys possess superiorthermo-mechanic performance. As such, shape-memory alloys can exist intwo different phases, with three different crystal structures (i.e.,twinned martensite, de-twinned martensite and austenite), and sixpossible transformations. Shape-memory alloy phase transformation isonly dependent on temperature and stress, thereby is a diffusionlesstransition between two phases that results in the special shape-memoryproperties of these alloys. It is a difference between a heating phasetransition and a cooling phase transition where some of the mechanicalenergy within a formed structure is lost in the phase transitionprocess. Hence, the material properties of the shape-memory alloy, suchas the alloy's composition and work hardening, defines the temperaturesrequired for a mechanical energy loss such that the deformationresultant from fabricating a structure can be reversed. Hence,shape-memory alloys are generally selected based on the needs of anapplication and an alloy's specific phase transformation temperatures.Such remarkable material properties are exactly why these shape-memoryalloys are widely used in applications, including medical applications.For example, Nitinol is widely used for this reason in medical stents.Nitinol is a shape-memory alloy, so can ‘remember’ its originalmanufactured shape and can return to the original shape with atemperature change. Nitinol has low elastic modulus, and its effectivestrain range is large thereby having a wider optimal phasetransformation force zone. Nitinol's low elastic modulus provides agreater range of phase transformation activation thus can be tuned forthe transformation such that adjustments can be made to the temperaturedifference such that a prong 70 can be compositionally or hardenadjusted such that the degree of grip of a prong 70 to a terminal pin 18and/or the pull force required for removal of a prong 70 from a terminalpin 18 can be customized. In the example of stents, a Nitinol stent witha transition temperature of 30° C. can be compressed at a firsttemperature ≤20° C. The Nitinol stent will stay compressed until thetemperature is increased to a second temperature >30° C. The Nitinolstent will then expand to its pre-set shape. If the Nitinol stent iskept cold during introduction into the body it will not expand, therebyfacilitating navigation through the vasculature to the stent placementsite within the vasculature. When the Nitinol stent is positioned at thedesired location it warms to the second temperature by means of bodyheat and self-expands to its original size. Alternatively, when a firsttemperature ≤20° C. is prohibitive, pending the tissue within which thestent is being positioned, a self-expanding Nitinol stent could be builtwith a phase transition temperature of, for example, 40° C. and theninserted at a first temperature of ≥20° C. but less than ≤30° C. Thesestents would have to be heated after delivery to the site to make themexpand, thereby achieving the same end result. Alternatively, whentemperature change itself is prohibitive, deployment of a stent canleverage the super-elasticity properties of Nitinol, wherein the sent iscompressed and constrained in a stent delivery system to preventpremature deployment, and then released of the compression andconstraint when positioned within the tissue wherein the self-expandingstent then returns to its original shape. In addition to stents, thesuper-elasticity property of Nitinol is use in other medicalapplications, such as catheters, super-elastic needles, and even forreconnecting the intestine after removing a pathology. The medicalindustry leverages the super-elasticity of Nitinol in theseapplications, as the massive elasticity of Nitinol permits compressionand constraint to an extremely small profile, and when the compressionand constraint is released, the Nitinol device then returns to itsoriginal size. As such, medical procedures such as the proceduresmentioned, are enabled by, for example, facilitating navigation ofcatheters in the vasculature, accurately positioning needles for biopsy,or even improving efficacy of intestinal reconnections. Hence, Nitinolcan be leveraged not only for its thermal phase transformationproperties, but also for its super-elasticity properties.

Referring once again to FIG. 14A, it is noted herein that environmentaltesting criteria for electronics/microelectronics of hermetically sealedAIMDs 14 are generally dictated by Military and Space SpecificationMIL-SPEC-883, which evaluates the ability of microcircuits (a part, apackaging or a device) to sustain harsh environments. For example, toassess the resistance of a part to extremes of high and lowtemperatures, and/or to the effect of alternate exposures to temperatureextremes, temperature cycling testing could be conducted. Suchtemperature cycling testing would be conducted, for example, on the AIMDheader block 118, the AIMD active electronic circuit board 106, and theEMI filter circuit board 106′ at temperatures ranging from −55° C. to+125° C. specified by the military standard. Hence, the terminal pinconnector 16 and/or its components comprising a shape-memory alloy, suchas the prong 70 of FIG. 14A, can be formed at a first temperature andopened to release from the terminal pin 18 at a second temperaturedifferent from the first temperature, the first and the secondtemperatures being within the temperature cycling test range. Insummary, the full temperature range of −55° C. to +125° C. Is usable toform a terminal pin connector 16 and/or its components comprising ashape-memory alloy at one temperature, and then remove the terminal pinconnector 16 and/or its components at another temperature, when anassembly comprising the terminal pin connector 16 and/or its componentsis deemed defective and requires replacement or rework. In the exampleof prong 70 of FIG. 14A comprising a shape-memory alloy, the prong 70would be capable of ‘resetting’ itself to an original shape so thatrelease from terminal pin 18 can be facilitated.

Referring once again to FIG. 14, one can see that header fixation blocks184 are attached to at least casing half 112 (header fixation blocks 184can alternatively be attached to the AIMD casing 32 after laser welding)on the right-hand side and on the left-hand side. The header fixationblocks 184 can be attached by laser welding, gold brazing or the like.Prior art header blocks generally have one or more holes 182 such that amaterial (for example, a polymer) can be squeezed into hole 182 andaround fixation blocks to affix and firmly secure a header block to theAIMD pulse generator. Such a prior art approach is a particular problemwhen an AIMD header block is deemed defective, for example, when adefective connector port, a defective BalSeal spring, or a cosmeticdefect is determined, as it becomes very difficult, if not impossible,to remove the AIMD header block for replacement without rejectabledamage to the AIMD 12. Once the AIMD header block is affixed, the AIMD12 is fully assembled, and includes all of its components, somesubstantially costly, such as the feedthrough, the battery, theelectronics, and the casing among others. Consequently, when a fullyassembled AIMD 12 is scrapped, a manufacturer takes a substantialfinancial hit to the bottom line.

As FIG. 14 illustrates, the header fixation blocks 184 comprise a hole182′, which is generally drilled and tapped with machined threads orequivalent such that when the AIMD header block 118 is positioned andaligned with holes 182′, a threaded fastener 186 can be inserted intoeach hole and screwed in to attach the AIMD header block 118 to eachheader fixation block 184 forming a reliable mechanical attachment ofthe header block 118 to the AIMD casing 32. The threaded fastener 186can comprise a set screw, the set screw comprising a head. The head ofthe set screw may comprise one of a Torx head, an allen head, a hex heador an equivalently structured head. The head of the set screw mayalternately comprise a flat head. The hole 182 of the AIMD header block118 may comprise a counter-bore such that, when the head is fastenedtightly, the AIMD header block 118 is firmly squeezed against the headerfixation block 184, which acts to prevent vertical dislocation of theAIMD header block 118 in addition to preventing the AIMD header blockfrom wobbling. There are two header fixation blocks 184 illustrated inFIG. 14, one on the right-hand side and one on the left-hand side, eachheader fixation block illustrating different embodiments. The headerfixation block 184 embodiment on the left-hand side of FIG. 14illustrates hole 182′ through the thickness of the long side of theheader fixation block. The header fixation block 184 embodiment on theright-hand side of FIG. 14 illustrates hole 182′ through the length ofthe long side of the header fixation block. Accordingly, the AIMD headerblock 118 would have a corresponding hole 182 for a threaded fastener186 to be positioned and screwed through hole 182 of the header block118 and hole 182′ of the header fixation block 184, thereby removablyaffixing the AIMD header block 118 to the AIMD pulse generator forming afully assembled AIMD 12. It is contemplated that different types, stylesand designs of header fixation blocks can be used alternately to theheader fixation blocks 184 shown in FIG. 14.

Referring once again to FIG. 14, when an AIMD header block 118 isconnected to the terminal pins 18 of the AIMD hermetically sealedfeedthrough 14 and is properly seated against the body fluid sidesurface of the AIMD pulse generator (not labelled), an electricallyinsulative sealant, such as an FDA-approved silicone or the like,generally resides between the AIMD header block 118 and the body fluidside surface of the AIMD pulse generator. The sealant is very importantas the sealant prevents electrical currents from flowing through anybody fluids that may migrate along either the terminal pins 18 of theAIMD hermetically sealed feedthrough of the AIMD 12 and/or into theterminal pin connectors 16. Accordingly, an appropriate amount ofsealant is preferred to prevent undesirable stray electronic currentleakage, to avoid unintended attenuation of biological sensing signals,or, in the case of a high voltage device like an implantablecardioverter defibrillator (ICD), to prevent high voltage flashovers.Having a suitable sealant is also important to a sustained biostabilityof materials present at this interface. For example, it is well known tothose skilled in the art that gold under voltage bias in an activelyfunctioning implanted AIMD is subject to electrolytic electromigrationin the presence of body fluid. For electrolytic electromigration of ametal to occur, moisture on the surface of the metal and a high electricfield across the metal are required. Such conditions are often caused bya combination of a voltage difference and a wet environment. It is notedherein that in the case of hermetic feedthroughs comprising gold braze,if the gold braze is under voltage bias and exposed to body fluid, theelectrolytic electromigration can occur. When an AIMD is activelydelivering electrical therapy, the gold braze of the hermeticfeedthrough of the AIMD is under voltage bias, satisfying the voltagedifference requirement for electrolytic electromigration. If the goldbraze is also exposed to body fluid, then the wet environmentrequirement for electrolytic electromigration is satisfied. Exacerbatingthe conditions of electrolytic electromigration of the gold is that bodyfluids comprise electrolytes, which are minerals such as sodium,calcium, potassium, chloride, phosphate, and magnesium that carry anelectric charge. Thus, the combination of the voltage bias across thegold braze and the presence of body fluid comprising electrolytes on thesurface of the gold braze, migration of gold from the braze is enabled,such that the migrating gold can electroplate undesirably redepositingelsewhere along the surface of AIMD, and can cause life-threateningpremature AIMD failure, premature power source depletion, or both.Sealants are therefore a critical adjunct of the present invention.

FIG. 15 is very similar to FIG. 3C in that we have an AIMD hermeticallysealed feedthrough 14 with a feedthrough capacitor 24 disposed on thedevice side. On the body fluid side, we have the terminal pin connector16 that is previously described which is now a part of an AIMD headerblock 118 (not shown). First of all, the terminal pins 18, 18′ aretwo-part pins. Two-part pins are more thoroughly described in U.S. Pat.No. 10,272,252, the contents of which are fully incorporated herein bythis reference. In this case, the AIMD header block 118 is different inthat the terminal pin connectors 16 are not actually disposed inside theAIMD header block 118. Instead, the terminal pin connectors 16 areelectrically and mechanically attached to the terminal pins 18 that arecoming through to the body fluid side insulator surface 36 of theinsulator 28 AIMD hermetically sealed feedthrough. On the right-handside, illustrated are terminal pins 18 that extend outwardly beyond thebody fluid side insulator surface 36 of the insulator 28 of which anelectrical and mechanical connection 128 is made a terminal pinconnector 16. Since the electrical connection 126 is on the body fluidside, the electrical connection must be biocompatible, hence, wouldtypically be made by one of laser welding or brazing. However, otherjoining processes can be used to make electrical connection 126,including micro welding, micro TIG welding, ultrasonic welding,resistance welding, friction welding, butt welding, arc welding, gaswelding, projection welding, flash welding, upset welding, solid statewelding, diffusion welding, induction welding, percussion welding,electron beam welding, multi-stage brazing, or reactive brazing. On theleft-hand side of FIG. 15, illustrated is a terminal pin connector 16that is pressed down onto an insulating washer 140, which is in turn, ispressed down against the body fluid side insulator surface 36 of theinsulator 28. The insulating washer 140 must also be biocompatible,biostable and non-toxic so would typically be made of a polyimide or anadhesive-backed polyimide. There are a number of other biocompatibleinsulating washer materials that could be used as an alternative, suchas biocompatible and biostable ceramics, plastics, polymers, paper,rubber, glass, glass fiber paper, glass ceramics, insulating metaloxides, diamond, and combinations thereof. The insulating washer 140 mayfurther comprise alumina (Al₂O₃), zirconia (ZrO₂) and/or variousstabilized or partially stabilized zirconia including ZTA and ATZ, fusedsilica, silicon nitride, alumina toughened zirconia, zirconia toughenedalumina, zirconium dioxide, yttrium-toughened zirconium oxide (Y-TZP),aluminum nitride (AlN), magnesium oxide (MgO), piezoceramic materials,barium zirconium titanium doped oxide, barium cerium titanium dopedoxide, sodium-potassium-niobate, calcium oxide, cerium oxide, titaniumoxide, apatite-wollastonite (A-W) glass ceramic, boron nitride, aluminasilicate, and combinations thereof. The insulating washer 140 may berigid (resists bending and forced shaping) or flexible (capable ofeasily being shaped and/or bent without breaking). As previouslydescribed, the electrical conductors 122, illustrated in the exemplaryFIG. 15 are leadwires, of the AIMD header block 118 must also bebiocompatible, biostable and non-toxic. Such electrical conductors 122are selected from the group consisting of titanium, tantalum, platinum,palladium, niobium, tantalum, gold, silver, iridium, rhenium, rhodium,tungsten, vanadium, zirconium and alloys or combinations thereof.Additionally, the electrical conductors 122 of the AIMD header block 118may further be an alloy selected from the group consisting of a cobaltchromium alloy, a cobalt chromium molybdenum alloy, a cobalt chromiumnickel iron molybdenum manganese alloy, a cobalt chromium tungstennickel iron manganese foil, a cobalt nickel chromium iron molybdenumtitanium alloy, a cobalt nickel chromium iron molybdenum tungstentitanium alloy, a cobalt nickel chromium molybdenum alloy, a copperaluminum nickel alloy, a gold platinum palladium silver indium alloy, anickel platinum alloy, Nitinol, a nickel titanium alloy, a nickeltitanium aluminum alloy, a niobium-titanium alloy, a platinum iridiumalloy, a platinum palladium gold alloy, a titanium aluminum vanadiumalloy, a titanium based aluminum iron alloy, a titanium based aluminummolybdenum zirconium alloy, a titanium based molybdenum niobium alloy, atitanium based molybdenum zirconium iron alloy, a titanium based niobiumzirconium alloy, a titanium based niobium zirconium tantalum alloy, atitanium molybdenum alloy, a titanium niobium alloy, a titanium platinumalloy, a titanium-based molybdenum zirconium tin alloy, MP35N®, Elgiloy®and biocompatible stainless steels, particularly 316L stainless steel.Referring now to the terminal pin connector 16, typically the connectorhousing 66, the clip 64 including its prongs 70 would be of titanium orsimilar biocompatible material, although any of the above biocompatibleand biostable materials may alternatively be used as well. The MRIconsiderations previously discussed are also applicable to theseterminal pin connectors and compliant termination structures.

It is contemplated that any of the terminal pin connectors and complianttermination structures disclosed in any of the drawings herein maycomprise a shape-memory alloy, for example, but not limited to, Nitinolor a Nitinol-based alloy. As previously disclosed, Nitinol enablesinsertion at a first temperature and extraction at a second temperature.Additionally, the super-elasticity properties of Nitinol previouslydisclosed could be a substantially beneficial aspect duringmanufacturing, as the massive elasticity of Nitinol enables compressionand constraint of AIMD components comprising Nitinol to a significantlysmaller profile, even a smaller completely flat or curved profile, tofacilitate insertion, and then when compression and constraint isreleased, the component returns to its original size. Moreover, Nitinolis capable of being locally modified to impart different springconstants at different points or locations on or about a specific siteor area of a component, including terminal pin connectors and complianttermination structures taught herein.

FIG. 16 is very similar to FIG. 15 except that both of the connectorhousings 86 have been pressed down against their respective insulatingwashers 140 against the body fluid side insulator surface 36 of thealumina insulator 28, and instead of clip 64, spring clips 64″ and 64′″are illustrated. Insulating washers 140 of the present application maycomprise a solid insulating structure (like mica, nylon, siliconerubber, plastic, ceramic, glass, composite, polytetrafluoroethylene,ethylene tetrafluoroethylene, polycarbonate, polyetherimide,polyoxymethylene, acetal, polyacetal, polyformaldehyde, phenolic andother similar non-metallic materials, and combinations thereof), a curedliquid insulating material (like epoxy, polyester, liquid siliconerubber, polyurethane, or other similar materials, and combinationsthereof), or an insulating adhesive washer (like polyimide, siliconepolyimide, polyurethane, silicone, polysulfide and other similarmaterials, and combinations thereof).

Referring to the left-hand side of FIG. 16, illustrated is a conductivesputter layer 42 (two sputter layers are illustrated by element 42 ofFIG. 16, however, one sputter layer may alternatively be used), which isselectively applied to the perimeter of the insulator 28 such that theconductive sputter layer 42 does not extend outwardly beyond the surfaceof the ferrule 26, thereby does not contact the terminal pin connector16. In this case, the insulating washer 140 could be removed becausethere is no longer a possibility of the connector housing 66 of theterminal pin connector 16 shorting out to the selectively appliedmetallization layer 42 of the insulator 28. Hence, the insulating washer140 on the left-hand side can be eliminated, thereby enabling theterminal pin connector 16 to be dropped down onto the body fluid sideinsulator surface 36 of the insulator 28.

Referring to the right-hand side of FIG. 16, a conductive sputter layer42 is applied to the full height of the perimeter of the insulator 28such that the conductive sputter layer 42 is present around the entireperimeter surface of the insulator 28. In this case, the conductivesputter layer 42 (which is illustrated as two sputter layers but couldbe one sputter layer) contacts both the terminal pin connector 16 andthe terminal ferrule 26. In this case, the insulating washer 140 isrequired to prevent shorting of the terminal pin connector 16 to themetallization layer 42; however, instead of insulating washer 140, theinsulating washer 140 could be eliminated and alternatively, be replacedby insulating coatings on the bottom of the connector housing 66 such asan insulative paint, an insulative polymer, a sputtered layer of ceramiclike alumina, an electrically insulating foil, or a vapor depositedinsulating film. Other coating processes may include: plasma spraying,thermal spraying, spin coating, dip coating, foil lamination, and thinfilm deposited layers. The electrically insulating coating may compriseone or more layers.

The connector housings 66, as described herein, may be metallic andtherefore, electrically conductive or may alternatively be anelectrically insulating material that has an electrically conductive ora metallic coating on its surfaces. The latter would make possibleminiature, sub-miniature and/or intricately designed connector housings66, which could conceivably be required for AIMDs like intraocularimplants, some brain stimulation devices, for example for babies orsmall children, or AIMDs having high count, high density and/or closepitched feedthrough conductor requirements. For example, the connectorhousing 66 could be plastic and then coated with conductive materialsvery much the same way that personal computers are made of plastic andthen have a plated electromagnetic interference shield. Furthermore, theconnector housing 66 could comprise a ceramic, a thermal-settingplastic, an injected molded plastic, polytetrafluoroethylene (PTFE),nylon, silicone rubber, plastic, ceramic, glass, composite,polytetrafluoroethylene, ethylene tetrafluoroethylene, polycarbonate,polyetherimide, polyoxymethylene, acetal, polyacetal, polyformaldehyde,phenolic and other similar non-metallic materials, and combinationsthereof. The connector housing 66 could also comprise a fiberglassmaterial. Irrespective of the insulating material, when an insulativematerial is used for the connector housing 66, it is contemplated thatan electrically conductive coating must be applied. The electricallyconductive coating may comprise an electrically conductive foil, ametallization, a plating or a vapor deposited film. The electricallyconductive coating may be applied either by painting, electroplating,bulk plating, or sputtering. As previously describe for clip 64, coatingprocesses for applying an electrically conductive coating to anelectrically insulating housing 66 may further include: physical vapordeposition, chemical vapor deposition, electrostatic spray assistedvapor deposition (ESAVD), electron beam physical vapor deposition(EBPVD), ion plating, ion beam assisted deposition (IBAD), magnetronsputtering, pulsed laser deposition, sputter deposition, vacuumdeposition, pulsed electron deposition (PED), plating, electrolessplating, electroplating, spraying, painting, plasma spraying, thermalspraying, spin coating, dip coating, metal foil lamination, and thinfilm deposited layers. The electrically conductive coating may compriseone or more layers. The one or more layers of the electricallyconductive coating may further comprise, but is not limited to, copper,tin, aluminum, stainless steel, titanium, gold, platinum, palladium,carbon, palladium alloys, gold alloys, niobium, tantalum, palladiumalloys, silver, sliver alloys, zirconium, hafnium, Nitinol, Co—Cr—Nialloys such as MP35N, Havar®, Elgiloy®, stainless steel, ZrC, ZrN, TIN,NbO, TiC and TaC, platinum alloys such as, but not limited to platinumiridium alloys, other associated alloys and the superalloys withnonlimiting examples such as the Hastelloys, Inconels, Monels,Waspaloys, and Renes, and combinations thereof. Body fluid side coatedconnector housing 66 would only include the biocompatible biostablematerials within this list, including the biocompatible and biostablematerials previously disclosed.

In the present invention, various spring-like elastically resilient andcompliant termination structures are taught, including prongs 70, clip64 and spring clips 64′, 64′, 64′″ and the like. Generally, these wouldcomprise one or more electrically conductive materials, however, couldalso be formed of various types of insulating materials described abovefor connector housing 66. It is understood that the materials, coatingsand processes disclosed for connector housing 66 above apply to all thespring-like elastically resilient and compliant termination structuresdescribed herein.

Referring once again to FIG. 16, in this embodiment, both the left-handside and the right-hand side connector housings 66 incorporate springclips 64″ (on the left-hand side) and 64′″ (on the right-hand side),neither spring clip comprising any prong(s) 70 as previously disclosed.The spring clip 64″ and 64′″ comprise elongated members 68″ instead ofprongs. The spring clip 64″ on the left-hand side comprises a concaveshape elongate member 68′, which is opposite the elongate shape 68″ ofthe spring clip 64′″ on the right-hand side, which comprises a convexshape as previously introduced in FIG. 5E. As previously taught for FIG.5E, either of these spring dips 64″, 64′″ can be slotted. The metallicconnector housing 66 of FIG. 16 could be of titanium or otherbiocompatible conductive metallic material previously disclosed, oralternatively, a plastic, composite, ceramic or polymeric non-conductivematerial plated, coated or otherwise covered with an electricallyconductive material, which can also be any of the previously disclosedmaterials; the spring clip 64″ and 64′″ reside within the connectorhousing 66 of the terminal pin connector 16. During AIMD header block118 insertion, electrical conductor 122 is inserted into the connectorhousing 66 of the terminal pin connector 16, slides into spring clip64′″ on the right-hand side and is gripped by the elongated member 68″,while the electrical conductor 122 inserted into spring clip 64″ on theleft-hand side is gripped by the radiused area 142 at the ends of theelongated member 68″. It is noted herein, that the grip of theelectrical conductor 122 disclosed above for the right and left-handsides clip embodiments also apply to the insertion of header blockleadwires or AIMD terminal pins.

FIG. 17 is very similar to FIGS. 15 and 16, except in this case, thespring clip 64′″ consists of one or more waved tines 79, as indicated.This is best shown in FIG. 18, which is an enlarged view of the springclip 64′″. FIG. 18 illustrates the waved tines 79 of the spring clip64′″ having a flat tine end, however, any configuration at the end ofthe tine may be used, such as curved, pointed or radiused. As previouslydescribed, it is very important that the spring rate be adjusted so thata tight grip be formed on the electrical conductor 122 (or leadwire orterminal pin) and at the same time, the elastic limit of the materialsof 64′″ are not exceeded. In other words, any permanent set to the timesof spring clip 64′″ of FIG. 18 should be avoided. Materials, such asconstantan (a copper-nickel alloy) cannot be used for the structureshown in FIG. 18, as, in FIG. 18, the structure is shown on the bodyfluid side, and constantan is not biocompatible. The structure shown,however, when use on the device side can comprise constantan. Instead,on the body fluid, any of the biocompatible, biostable and non-toxicmaterials disclosed previously for the electrical conductors 122 orleadwires of the AIMD header block 118 may be used as long as the designbeing used has a spring constant that supports the intent of theconnection. The spring constant of any material used in any of theterminal pin connector 16 designs disclosed herein, including the designof the presently disclosed FIGS. 17 and 18 may be adjusted for optimalspring characteristics and durability by one of: varying materialthickness, diameter, or size of the prongs, tines, fingers or walls ofthe structure; plating with a complementary material or materials; heattreating; degree of engagement surface area; or combinations thereof. Inthe specific case of Nitinol, in addition to the above spring constantadjustment options, the spring constant of a monolithic Nitinolstructure may also be adjusted by laser-processing, wherein a laser isused to change the composition of the Nitinol locally within themonolithic structure in order to add multiple memories within themonolithic Nitinol structure. By laser-processing, the localizedcompositional changes can provide customized elasticity and or phasetransition temperature to each prong in the structure or can providedpairing of elasticities or phase transition temperatures between two ormore prongs so that flexibility in force required for insertion orretraction is imparted to the monolithic structure. Further, if an AIMDapplication has special insertion and/or retraction requirements, one ormore prongs can even be selectively removed from the monolithic Nitinolstructure to achieve a target insertion and/or retraction force. WhileFIG. 18 shows a specific embodiment, it is understood by one skilled inthe art that the shape of the prongs/tines can be of any configurationdesigned to achieve the required spring constants.

Referring now to U.S. Pat. No. 6,987,660, the contents of which arefully incorporated herein by this reference, one will see that the '660patent teaches contact springs (136). The contact springs (136) areinserted into the active passageways of feedthrough capacitors (100,400) to effect an electrical connection between a hermetic seal terminalpin (122) and the capacitor active passageways inside the diametermetallization (110), and, in turn, to the capacitor active electrodeplates (106). The '660 patent teaches that the contact springs (136) areto facilitate low cost, high-speed manufacturing, and to also eliminateseveral expensive steps such as elimination of insulating washers andcentrifuging of thermal setting conductive polymers, which are timeconsuming and messy processes. The '660 patent never suggests, teachesor otherwise mentions or anticipates removable AIMD active electroniccircuit boards 106, EMI filter circuit boards 106′ or AIMD header blocks118 as taught by the present application. The words “circuit board” or“header block” never even appear in the '660 patent. At the time offiling, the '660 patent inventors did not contemplate or appreciate theneed for removable AIMD circuit board(s) 106, 106′ or a removable AIMDheader block 118. Furthermore, the '660 patent teaches away fromremovability in that the feedthrough capacitor (100, 400) is notsuggested or taught to ever be removable. As the '660 patent states incolumn 8, lines 38 to 40: “[t]here is no reason to remove thefeedthrough capacitor (400) once it is installed”, removability of thefeedthrough capacitor was not considered, as the feedthrough capacitorsof the '860 patent are not capable of removal without damaging them,thereby dispelling any notion of feedthrough capacitor removal.

Referring once again to FIGS. 16 and 17, the terminal pin connectors 16are shown on the body fluid side, but it is contemplated that they couldbe attached to an AIMD active electronic circuit board 106, or an EMIfilter circuit board 106′ as implied by the device side portion of FIG.17. Regarding the device side portion of FIG. 17, the circuit boards106, 106′ would reside inside the hermetically sealed casing 32 (notshown) of the AIMD 12 and the terminal pin connector 16 would,therefore, not need to be biocompatible. Accordingly, when disposed onthe device side of an AIMD, the terminal pin connectors 16 of FIGS. 16and 17 do not need to comprise biocompatible, biostable and non-toxicmaterials, thus constantan could be effectively used.

In FIGS. 18 and 19, circuit board 106, 106′ need not be perpendicular tothe AIMD hermetically sealed feedthrough 14 and its terminal pins 18,18′ (two-part terminal pins). Alternatively, the terminal pins 18′(device side part of the two-part pin) could be bent at an angle (suchas approximately a 90° angle) such that they could engage AIMD activeelectronic circuit board 106 that may be lying parallel to the AIMDhermetically sealed feedthrough 14.

FIG. 19 is another embodiment illustrating the terminal pin 18, 18′comprising a compliant termination structure 81 having a spring-likeelastically resilient press-in zone that can be inserted or ‘press fit’into a conductive plated or terminated circuit board via hole 109 havingcircuit traces (not shown) routed to them. Such a compliant terminationstructure 81 can be integrated with the device side portion of atwo-part pin 18′, while the body fluid side portion of a two-part pin 18comprises a biocompatible biostable non-toxic terminal pin, therebyproviding a unique cost-effective AIMD hermetically sealed feedthrough14 embodiment. While the compliant termination structure 81 shown has aspecific configuration, any compliant termination designs featuring anelastic-resilient spring-like behavior during insertion may be used. Inthis embodiment, the circuit board can comprise metallic eyelets 194,which are robust and allow for the insertion of the complianttermination structure 81 of the terminal pins 18′. It is understood thatconnector housings 66 could be used instead of metallic eyelets 194.Additionally, the AIMD active electronic circuit board 106 may comprisecircuit board via holes 109, some of which can be eyelets 194, and someof which can be connector housings 66. In this case, the use of atwo-part pin is ideal, as the terminal pin 18′ disposed on the deviceside need not be biocompatible, thereby conductive material selection isunrestricted, allowing material selection to consider spring-ratesconducive to ease of manufacture of potentially sensitive or complexcompliant terminations 81 designs. Referring once again to FIG. 19, onewill see that the orientation of the AIMD active electronic circuitboard 108 is such that instead of lying parallel to and in-line with thelongitudinal axis of the terminal pins 18′, the circuit board 106 ispositioned perpendicular to the longitudinal axis of the terminal pins18′. Hence, as will be further described herein, either one of an AIMDactive electronic circuit board 106, an EMI filter circuit board 106′ orboth an AIMD active electronic circuit board 106 and an EMI filtercircuit board 106′ can be disposed at, near or adjacent an AIMDhermetically sealed feedthrough. In this case, the feedthrough capacitor24 would be removed and EMI filtering would be done by the EMI filtercircuit board 106′.

Referring once again to FIG. 19, illustrated on the left-hand side is avia hole eyelet 194, which can be a formed eyelet (that is, a thinstamped, machined or the like) or, as shown on the right-hand side, anelectroplated or metallized via hole 109 of any type known in the priorart can be provided into which a connector housing 66 may be inserted.Alternatively, on the right-hand side, a much heavier duty eyelet 194can been inserted instead of connector housing 66, which can either besoldered (or otherwise equivalently electrically connected), or,depending on the size, material of construction and circuit boardmaterial and/or thickness, can be press-fit into via hole 109. A heavierduty eyelet 194 or a connector housing 66 serves to mitigate stressesimparted during pin insertion 18′, thereby inhibiting crack initiationpreventing cracking or damaging of delicate AIMD active electronic orEMI filter circuit boards 106, 106′. As such, in accordance with theembodiments of the present application, this heavier eyelet structure orthe connector housing, may comprise at least a partial flange, asillustrated. While FIG. 19 shows a specific embodiment the complianttermination structure 81 of terminal pin 18′ engaging the eyelet 194 orconnector housing 66, it is understood by one skilled in the art thatthe shape of the terminal pin compliant termination structure 81 can beof any configuration designed to achieve the required eyelet 194 orconnector housing 66 engagement.

FIG. 19A is another embodiment of a compliant termination structure 81′.The compliant termination structure 81′ may be monolithically formedwhen terminal pins 18, 18′ are formed (not shown), or alternatively maybe separately formed and joined to terminal pins 18, 18′ by a weld or abraze (the weld or braze is labelled 144 in FIG. 19A). Similarly, theembodiments of the compliant termination structures 81′ of FIGS. 19 and19B-19D can be monolithically formed when terminal pins 18, 18′ areformed, or alternatively may be separately formed and joined to terminalpins 18, 18′ by a weld or a braze.

FIG. 19B is another embodiment of a terminal pin 18, 18′ with acompliant termination structure 81″. In this embodiment, the terminalpin 18, 18′ extends through the compliant termination structure 81″ andillustrates a first weld or braze 144 and/or a second weld or braze 144′for attachment of the compliant termination structure 81″ to terminalpin 18, 18′.

FIG. 19C is yet another embodiment of a terminal pin 18, 18′ with acompliant termination structure 81′″. In this case, having inwardlyangled prongs.

FIG. 19D is yet another embodiment of a terminal pin 18, 18′ with acompliant termination structure 81″ ″ that has a rounded prong ends thatfacilitate insertion.

It is noted herein that, when any embodiments of terminal pin connectors16, terminal pins 18, 18′, 18 gnd or the compliant terminationstructures 81′ are used on the body fluid side of the AIMD, theembodiments must be made of biocompatible, nontoxic and biostablematerials. Likewise, when any embodiments of terminal pin connectors 18,terminal pins 18, 18′, 18 gnd or the compliant termination structures81′ are used on the device side, which is the inside of the AIMD, theembodiments do not need to be biocompatible, nontoxic or biostable. Itis also understood that any compliant termination structures disclosedherein including the compliant termination structures of FIGS. 19-19Dcan be separately manufactured from the terminal pin 18, 18′, 18 gnd oralternately could be made as part of the terminal pin 18, 18′, 18 gnd inone monolithic structure. It is also contemplated that any complianttermination structure disclosed herein including the complianttermination structures of FIGS. 19-19D can be integrated into any AIMDterminal pin or AIMD header block electrical conductor or leadwire forinsertion into connector housings 66, circuit board eyelets 194, orcavities 180 taught herein.

FIG. 20 illustrates a connector housing 66 of an exemplary terminal pinconnector 16 of the present application with an alternative prong 70, asillustrated. It is noted herein that any of the connector housingembodiments of the present application may be used instead of theconnector housing shown. The prongs 70 of FIG. 20 are shown incross-section. It is contemplated that they can be 2, 3, 4 or even “n”number of prongs. Prongs 70 could be laser welded or brazed 144 to clip64, as indicated, or prongs 70 could alternately be crimped. If disposedon the device side (Inside the hermetically sealed AIMD casing 32), thenthe mechanical and electrical connection of element 144 need not bebiocompatible and could comprise solder, thermal-setting conductiveadhesives and the like. However, if prongs 70 reside on the body fluidside, then mechanical and electrical would require a laser weld 144.

FIG. 21 is similar to FIG. 20, except in this case, the prongs 70 arenow attached to a spring clip 64′. The spring clip 64′ providesadditional insertion capability to both sides of its structure such thatprongs 70 can be inserted into a connector housing 66 as illustrated orinto a circuit board via hole 109 or a cavity 181 (not shown) andterminal pin 18, as illustrated (or a two-part terminal pin either 18 or18′ not shown), can be inserted into spring clip 64′. In other words,there would no longer be a need for the mechanical and electricalconnection previously labelled in FIG. 20 as element 144. The distal end62′ of the terminal pin 18 is inserted Into the spring clip 64′, makinga robust, alternative mechanical and very low resistance electricalconnection 181. When the prongs 70 are inserted inside the connectorhousing 66, the spring rate and the tolerances are adjusted such thatthe prongs 70 end up compressed very tightly against the inside diameterof the housing 66. This makes for a very robust alternative mechanicaland electrical connection, which can either be on a circuit board or onan AIMD header block.

FIG. 22 illustrates an alternative AIMD hermetically sealed feedthroughcomprising co-sintered conductive paste-filled vias 146, which areformed by co-sintering a conductive paste residing in the via of theinsulator 28 at the same time that the insulator 28 is sintered. Theco-sintered conductive paste-filled via 146 can be of a substantiallypure platinum or a ceramic reinforced metal composite (CRMC).Co-sintered platinum filled vias are described by U.S. Pat. Nos.8,653,384; 8,938,309; 9,233,253; 9,352,150; 9,511,220; 9,889,306 and9,993,650, the contents of which are fully incorporated herein by thesereferences. Co-sintered ceramic reinforced metal composite (CRMC)conductive vias are described by U.S. Pat. Nos. 10,272,253 and10,249,415, the contents of which are also fully incorporated herein bythese references. Referring once again to FIG. 22, illustrated are twoembodiments comprising a cavity 181, wherein the distal end ofelectrical conductor 122′ comprises a compliant termination structure (aspring-like elastically resilient structure) having prongs 70 insertedinto a counterbore 180 of the co-sintered conductive paste-filled vias146 forming the cavity 181. The prongs 70, which are inserted intocavity 181, provide a robust, mechanical and low resistance electricalconnection.

Referring once again to FIG. 22, illustrated on the left-hand side ofFIG. 22 is a co-sintered conductive paste-filled via 146 of theinsulator 28 having two portions: a device side portion having a smalldiameter, and a body fluid side portion having a diameter larger thanthe device side portion. Within the body fluid side portion, acounterbore 180 is made forming the cavity 181. The diameter of thecavity 181 is larger than the diameter of the device side portion of theco-sintered conductive paste-filled via 146, but smaller than thediameter of the device side portion of the co-sintered conductivepaste-filled via 146. On the right-hand side of FIG. 22, illustrated isa co-sintered conductive paste-filled via 146 having a constant diameterover the length of the via of the insulator 28 (in other words, the samediameter from the body fluid side insulator to the device side insulatorsurface). The diameter of the co-sintered conductive paste-filled via146 is larger than the diameter of cavity 181. Similar to the left-handside, the prongs 70 are inserted into cavity 181 thereby providing arobust, mechanical and low resistance electrical connection. The hole ofco-sintered conductive paste-filled via 146 on both sides of theinsulator 28 can be formed in the insulator 28 in a green state by oneof a drilling, a punching, a machining, a waterjet cutting, orcombinations thereof.

Referring once again to FIG. 22, forming the via configuration ofco-sintered conductive paste-filled via 146 on the left-hand side mayrequire a double forming (for example, a double drilling) or amulti-forming step. For the via configuration of the co-sinteredconductive paste-filled via 146 on the right-hand side of insulator 28,wherein the via configuration on the right-hand side is of constantdiameter, the entire via configuration of the co-sintered conductivepaste-filled via 146 may be drilled through the thickness of the greeninsulator in one drilling step thus extending the via configuration ofthe insulator 28 to the device side insulator surface and to the bodyfluid side insulator surface. Once the via configuration is formed, bothvia configurations are then filled with a conductive paste-fill.Counterbore 180 may then be formed in either the left-hand sideconductive paste-filled via, the right-hand side conductive paste filledvia or both, forming the cavity 181, which is then followed byco-sintering of the conductive paste-fills with the sintering of thegreen insulator 28. Counterbore 180 alternatively may be formed ineither the left-hand side conductive paste-filled via, the right-handside conductive paste-filled via or both, after co-sintering with thesintering of the green insulator 28.

Instead of using one of the above formation processes to form the viaconfiguration of the conductive paste-filled via after co-sintering theconductive paste-filled via with the sintering of the green insulator 28thereby forming a co-sintered paste-filled via 146, the viaconfigurations may be alternatively formed at the same time as the greeninsulator is formed by either pressing or molding the insulator 28 usingappropriately designed fixtures and tooling designed to include the viaconfigurations. Pressing may be done by one of hydro-static pressing,hot pressing, cold pressing, die pressing, or mechanical pressing.Molding may be done by powder injection molding, ceramic injectionmolding, or hot wax molding. Once the via configurations are co-formedwith the green insulator 28, then one or more via configurations may befilled with a conductive paste-fill. The conductive paste-filling stepmay comprise filing the open volume of at least one entire viaconfiguration or, alternatively, may at least partially fill at leastone via configuration. Insulator 28 may comprise one or more viaconfigurations, having an open via configuration volume that completelyfills the available open via configuration volume; or, alternatively,each open via configuration may be filled with different volumes of theavailable open via configuration volume or all open via configurationsmay be filled to the same volume of the available open via configurationvolume. At least one via configuration may be left open without anyconductive paste-fill to later accommodate some other component, suchas, but not limited to, a terminal pin 18. Counterbore 180 may bepre-formed in via configuration that has been filled with conductivepaste-fill by adding additional pressing or molding steps and/oradditional pressing and/or molding fixtures and/or tooling.Alternatively, counterbore 180 may be formed in the co-sinteredconductive paste-filled via 146 after co-sintering with the sintering ofthe insulator 28 by one of drilling, punching, machining, waterjetcutting, or combinations thereof.

Referring once again to FIG. 22, it is understood that the electricalconductor 122′ and the prongs 70 shown on the body fluid side mustcomprise a biocompatible, biostable and non-toxic material. It iscontemplated, however, that such conductors 122′ and the prongs 70 couldalso be used on the device side, which is inside the AIMD casing 32, toattach components such as an AIMD active electronic circuit board 106and/or an EMI filter circuit board 106′ (not shown), wherein at leastone conductor 122′ would be attachable to a hermetically sealedfeedthrough 14 having a corresponding cavity 181 on the device side.This would allow either of the circuit boards 106 and 106′ or both thecircuit boards 106 and 106′ to be attachable to at least one electricalconductor 122′ so that the prongs 70 of the electrical conductor 122′may be plugged into cavity 181 of the hermetically sealed feedthrough 14as illustrated by FIG. 22. When the electrical conductor 122′ isdisposed on the device side inside the AIMD casing 32, it iscontemplated that the electrical conductor 122′ and its prongs 70 neednot be biocompatible and could instead comprise less expensivecost-effective electrically conductive materials, including, but notlimited to, gold-plated constantan, beryllium copper, or any of thepreviously disclosed electrically conductive materials. It is furthercontemplated that counterbore 180 may be formed on one of the body fluidside of a co-sintered conductive paste-filled via 148, on the deviceside of a co-sintered conductive paste-filled via 146, or on both thebody fluid and the device sides of the co-sintered conductivepaste-filled via 146. Likewise, any electrical conductor 122′,regardless of the compliant termination structure may also be disposedon one of the body fluid side of a co-sintered conductive paste-filledvia 146, on the device side of a co-sintered conductive paste-filled via146, or on both the body fluid and the device sides of the co-sinteredconductive paste-filled via 146. Additionally, it is also contemplatedthat any connector housing 66 disclosed herein may be inserted in atleast one cavity 181 of a co-sintered conductive past-filled via 146 onone of the body fluid side of a co-sintered conductive paste-filled via146 or on a device side of co-sintered conductive paste-filled via 146.In summary, FIG. 22 illustrates a way of plugging either an electricalconductor 122′ of either an AIMD active electronic circuit board 106 oran EMI filter circuit board 106′ or a body fluid side AIMD header block118 or combinations thereof directly into at least one cavity 181 of aco-sintered conductive paste-filled via 148 of an insulator 28 of ahermetically sealed feedthrough 14 of an AIMD 12, thereby forming amechanical and low resistance electrical connection.

Referring once again to FIG. 22, on the left-hand side, one can see thatthere are two layers to the co-sintered conductive paste-filled filledvia 146. The two layers of the co-sintered conductive paste-filledfilled via 146 may comprise one ceramic reinforced metal composite(CRMC) 147 and one essentially pure platinum 146. CRMCs 147 mayencompass 1, 2 or even “n” number of layers in order to buffer anymismatches in thermal coefficients of expansion between the greenalumina insulator 28 and the essentially pure platinum 146 during theco-sintering process and on cool-down to room temperature. CRMC pastesare more thoroughly described in U.S. Pat. No. 10,249,415 and itsfamily, which are incorporated herein by reference. It is understood byone skilled in the art that the via configurations of the co-sinteredconductive paste-filled vias shown on the body fluid side couldalternately be used on the device side. Additionally, it is contemplatedthat the cavity 181 could be present on both sides by duplicating thebody fluid side portion of the via configuration on the device sideportion of the insulator 28. The teaching of cavity 181 and viaconfigurations illustrated in FIG. 22 herein are not intended to belimiting in any way.

FIG. 23 is very similar to FIG. 22, except in this case, the electricalconductor 122 is inserted into the connector housing 66′ such that theelectrical conductor 122 is engaged with one or more spring fingers 51making a mechanical and electrical connection with the electricalconductor 122. At the same time, the prong 70 makes an electricalconnection with the cavity 181 formed by the counterbore 180 of aco-sintered conductive paste-filled via 146, as previously described forFIG. 22.

FIG. 24 is similar to FIG. 23, except in this case, the electricalconductors 122 are engaged in a connector housing 66″ with one or moreintegrally formed spring fingers 51 that are oriented in differentdirections as illustrated. In this case, the connector housing 68″ hasbeen gold brazed 148 to the co-sintered conductive paste-filled via 146.

Referring now to FIGS. 22, 23 and 24, it is contemplated that acounterbore 180 can be made in any co-sintered conductive paste-filledvia 146, either on the device side, on the body fluid side or on boththe device and the body fluid sides of the co-sintered conductivepaste-filled via 146; the counterbore 180 thereby forming a cavity 181,the cavity 181 capable of incorporating, for example, a spring clip 64′″having waved tines 79 (wavelike undulations), as illustrated in FIG. 18,or any other compliant termination structure taught herein. It will alsobe appreciated, referring back to FIGS. 4A, 4B and 4C, that the base 68of clip 64 could be press fitted into the cavity 181 of a co-sinteredconductive paste-filled via 146 formed by the counterbore 180 such thatan electrical conductor 122 could be inserted. There are a number ofembodiments that are possible in light of the teachings of thisdisclosure, the embodiments disclosed herein being only exemplary andnot meant to be limiting in any way.

FIG. 24A is similar to FIGS. 22-24, except that now a connector housing66 and/or a terminal pin connector 16 can be disposed either on the bodyfluid side or the device side of a. Such connector housings 66 and/or aterminal pin connectors 16 are electrically connected one or moreco-sintered conductive paste-filled vias 146, the one or moreco-sintered paste filled vias 16 comprising one of a pure platinumco-sintered conductive paste-filed via 146, a pure platinum co-sinteredconductive paste-filled via 146 having a CRMC 147 co-sintered layer, orcombinations thereof. FIG. 24A illustrates an embodiment where aconnector housing 66 comprising an integrally formed post 77 co-sinteredwithin a co-sintered conductive paste-filled via 146 (see the embodimentshown on the body fluid side of the left-hand side of FIG. 24A and theembodiment on the device side of the right-hand side of the co-sinteredconductive paste-filled via 146 of FIG. 24A). Alternatively, theconnector housing 66 may be brazed or welded for attachment to theco-sintered conductive paste-filled via 146 (see the embodiment shown onthe body fluid side of the right-hand side of FIG. 24A and theembodiment on the device side of the left-hand side of the co-sinteredconductive paste-filled via 146 of FIG. 24A). FIG. 24A also illustratesthat either the connector housings 66 or the electrical conductors 122can comprise compliant termination structures (see the exemplary clipscomprising prongs 70 within connector housings 66 on the device and bodyfluids sides on the left-hand side of FIG. 24A, and prongs 70 of thecompliant termination structure at the distal end of the terminal 18 onthe right-hand side of FIG. 24A). When such compliant terminationstructures are used on the body fluid side, the compliant terminationstructures would be made of a biocompatible, nontoxic and biostablematerial. Likewise, when the compliant termination structure is used onthe device side inside the AIMD, the compliant termination structures donot have to comprise a biocompatible, nontoxic or biostable material.

FIG. 25 is very similar to FIG. 20, except that the prongs 70 at thedistal end 62 of terminal pin 18 have a different shape. One can seethat the prongs 70 are relatively straight, but the connector housing 66now has a chamfer 150. When the prongs 70 are inserted into the chamfer150, the chamfer compresses the prongs 70, such that they are insertedinto cavity 152 where they elastically contact the sidewalls of cavity152 forming a robust mechanical and electrical connection. Referringonce again to FIG. 25, illustrated is a closed bore connector housing66, however, and an open bore connector housing 66 can alternatively beused. It will be appreciated that the embodiment illustrated in FIG. 25could be disposed on the device side inside an AIMD casing 32 (notshown), wherein the connector housing 66 connects an AIMD feedthroughconnector assembly 10 or a feedthrough capacitor connector assembly 20and an AIMD active electronic circuit board 106 or an EMI circuit board106′ or both an AIMD active electronic circuit board 106 and an EMIcircuit board 106′. Additionally, the embodiment illustrated in FIG. 25could be disposed on the body fluid side of an AIMD 12 wherein theconnector housing 66 connects an AIMD feedthrough connector assembly 10or a feedthrough capacitor connector assembly 20 and an AIMD headerblock 118. The connector housing 66 can be disposed and/or attached inaccordance with the embodiments and teachings disclosed herein.

FIG. 26 illustrates an embodiment similar to FIG. 25, except the chamfer150 configuration of the connector housing 66 is different. When theprongs 70 at the distal end 62 of the terminal pin 18 are inserted intothe chamfer 150 configuration of the connector housing 66 of FIG. 26,the prongs 70 are mechanically compressed as the prongs 70 slide alongthe chamfer 150 ultimately electrically engaging the inside diameter ofthe narrowed through-bore along longitudinal axis A-A.

FIGS. 27 and 28 are taken from FIGS. 51 and 52 of U.S. Pat. No.10,272,252, the contents of which are fully incorporated herein by thisreference. Referring to FIG. 27, one can see that there is an AIMDhermetically sealed feedthrough 14 which may have one-part or two-partterminal pins 18, 18′, as has been previously disclosed. Disposed on thedevice side is an EMI filter circuit board 106′. The EMI filter circuitboard 106′ may have one or more internal ground electrode plates 156, asillustrated. Circuit board ground electrode plates 156 are morethoroughly described in U.S. Pat. Nos. 8,195,295 and 10,272,252, thecontents of which are fully incorporated herein by these references.Referring once again to FIG. 27, the EMI filter circuit board 106′ maybe disposed against at least one of the device side of the insulator 28and/or the ferrule 28 or an insulating washer (not shown) may bedisposed between the EMI filter circuit board 106′ and at least one ofthe insulator 28 and the ferrule 26. Alternatively, the EMI filtercircuit board 106′ may be disposed along the terminal pins 18 and 18 gndat some distance from the ferrule 26 or the insulator 28 therebyproviding a gap between the EMI filter circuit board 106′ and at leastone of the insulator 28 and the ferrule 26. As shown in FIG. 27, the EMIfilter circuit board 106′ is immediately adjacent both the aluminainsulator 28 and the ferrule 26, but as has been stated, it need not beadjacent. Rather, it could be spaced away, even at some substantialdistance, from one of the insulator 28, the ferrule 26, or both.

Referring once again to FIG. 27, one can see that there is a terminalpin connector 16 associated with each one of the active terminal pins 18and also the ground terminal pins 18 gnd and 18 gnd′. It is contemplatedthat, while two ground terminal pins are illustrated, any number (n) ofground terminal pins can be present. As previously described, theseterminal pin connectors 16 would be populated on the main AIMD activeelectronic circuit board 106 (not shown). Accordingly, each one of theactive terminal pins 18 would be routed to active traces 162 of the AIMDactive electronic circuit board 106. At least one ground terminal pin 18gnd (or 18 gnd′) would be routed to an AIMD active electronic circuitboard 106 ground electrode plate 52, ground trace or ground plane (notshown). As previously indicated, this is useful for AIMDs 12 thatsometimes use the AIMD casing 32 as an electrode. The active pins areterminal pins 18 a through 18 f. The left-hand side ground terminal pin18 gnd resides in a ferrule counterbore. The ground terminal pin 18 gndmay alternatively be attached to the device side ferrule surface 26′ andmay even comprise a nailhead feature to facilitate ground terminal pinattachment (not shown). The right-hand side ground terminal pin 18 gnd′goes all the way through the hermetically sealed feedthrough 14 suchthat it can also be connected on the body fluid side. Some of theseactive terminal pins 18 a-18 f may be used to sense biological signals.Others may be used to provide therapeutic pulses or in the case of animplantable cardioverter defibrillator (ICD), pairs of these leads couldbe used to provide high voltage cardioversion therapy to cardiovert theheart from dangerous rhythms to normal sinus rhythm. Referring onceagain to FIG. 27, it is contemplated that in an ICD application,terminal pin 18 a could be routed to a distal shocking electrode, forexample, in the right ventricle of the superior vena cava. The AIMDactive electronic circuit board 106 could be programmed such that theopposite polarity of the shocking biphasic wave form could be applied toterminal pin 18 gnd. This is called a ‘hot can’ wherein, the shockingvector would be between the distal electrode located inside the heart,back to the AIMD casing 32. So, by having terminal pin 18 gnd connectedto the AIMD active electronic circuit board 106 (not shown), thisprovides for a number of alternatives. Pacing vectors like this are alsovery important for spinal cord stimulators where sometimes the AIMDcasing 32 itself is used as part of the pacing vector.

Referring once again to FIG. 27, one will see that the EMI filtercircuit board 106′ has a number of filter capacitors 154. As describedin U.S. Pat. Nos. 10,272,252 and 8,195,295, these could be MLCCs 154,otherwise known as monolithic multilayer ceramic capacitors, or X2Yattenuators 300 or flat-thru capacitors 400. Each one of thesecapacitors 154, 300, 400 has one or more active electrode plates thatare electrically connected to active terminal pins 18 a through 18 f.Referring once again to FIG. 27, this particular embodiment has six (6)poles (6 active terminal pins) with two (2) ground terminals 18 gnd and18 gnd′. As illustrated in FIG. 27, the ground terminal pins 18 gnd and18 gnd′ are either laser welded 160 or gold brazed 165 to the ferrule26. Brazing or welding the ground pins 18 gnd and 18 gnd′ permitspenetration through any oxides present on the ferrule 26 thus forming avery low resistance metallurgical electrical connection. Thismetallurgical electrical connection has been shown to be very stable andgenerally will not form oxides over time. Further, by using ground pinscomprising a suitable oxide-resistant material, such as platinum, afurther essentially oxide-free electrical connection can be made to theground pin. For example, in addition to the already mentioned AIMDcomponents, that is, circuit boards or header blocks, and the electricalcomponents: MLCCs, X2Y attenuators or flat-thru capacitors, theessentially oxide-free electrical connection can be made between theoxide-resistant ground pins 18 gnd and 18 gnd′ to a ground electrode, aground circuit trace, a ground via of a circuit board, or to an edgeground metallization of the circuit board or of the electricalcomponents. The essentially oxide-free electrical connection can be adirect electrical connection to the oxide-resistant ground pin, or,alternatively, the electrical connection may be made using an electricalconnection material such as a solder, a thermal-setting conductiveadhesive or the like. Hence, for the above reasons, all ground terminalpins of the AIMD device can comprise an oxide-resistant, namely anessentially oxide-free, material. For example, the oxide-resistantground terminal pins 18 gnd and 18 gnd′ can comprise a noble metal.Additionally, the oxide-resistant ground pins 18 gnd and 18 gnd′ cancomprise platinum, gold, tungsten, iridium, palladium, niobium,tantalum, ruthenium, rhodium, silver, osmium, and alloys or combinationsthereof. Further, the oxide-resistant ground pins 18 gnd and 18 gnd′ cancomprise platinum based materials including platinum-rhodium,platinum-iridium, platinum-palladium, or platinum-gold, includingnaturally occurring alloys such as platiniridium (platinum-iridium),iridiosmium and osmiridium (iridium-osmium). It is important to noteherein that the oxide-resistant ground pins are hermetic (see 118 gnd′)and provide strong mechanical and low resistance electrical attachmentto the ferrule 26. Importantly, such attachment of oxide-resistantground pins 18 gnd to the ferrule 26 further provides very low impedanceconnections at high frequencies, which is necessary to divert dangerouselectromagnetic interference (EMI) signals. Of significance is thatoxide-resistant ground terminal pins 18 gnd and 18 gnd′ can themselvesprovide for connections having low resistance and low impedance at highfrequencies regardless of the metal used to form the ferrule, providingnew design opportunities not only for AIMDs, but other types of “smart”medical devices, whether implanted, temporarily implanted, or externalthe body, for example, sensors, monitors, identification tags,recorders, controller, artificial organs and the like. Suchoxide-resistant materials should also be capable of high processingtemperatures to sustain oxide formation resistance.

FIG. 27A is taken from section 27A-27A of FIG. 27. It shows analternative connection to connect the ground pin 18 gnd to the at leastone ground plate 156 of the EMI filter circuit board 106′. In this case,the EMI filter circuit board 106′ has a circuit board edge metallization500, which is electrically connected to its at least one ground plate156, in this case, an internal ground plate. It should be noted thatthere may be a plurality of internal ground plates and/or there may alsobe one or more external ground plates, for example, the external groundplates are disposed either on the top surface, on the bottom surface oron both the top and the bottom surfaces of an EMI filter circuit board106′. Importantly, these ground plates 156 provide a low impedance pathfor the filters (an MLCC capacitor 154, an X2Y attenuator 300, aflat-thru capacitor 400, and combinations thereof) to divert dangerousEMI currents while at the same time, shielding the insulator 28 AIMDhermetically sealed feedthrough 14 from direct penetration of highfrequency RF-radiated noise (EMI). Referring once again to FIG. 27A, onecan see that there is an electrical connection material 504 thatelectrically connects the edge metallization 500 of the circuit board(which is also an external metallization) to the ground terminal pin 18gnd. This electrical connection material 504 may comprise a solder, athermal-setting conductive adhesive, a conductive epoxy, or any othersuitable type of electrical connection material 504. In addition, theground terminal pin 18 gnd could be wire bonded to the circuit boardedge metallization 500 or to a conductive pad (not shown).

FIG. 27B is taken from section 27B-27B of FIG. 27. This illustrates theEMI filter circuit board 106′ with edge metallization 500 as previouslydescribed in FIG. 27A. In this case, the electrical connection material504, is a thermal-setting conductive adhesive, including conductivepolyimides and conductive epoxies, which has been used to connect thecircuit board edge metallization 500 directly to the device side ferrulesurface 26′. For active implantable medical devices 12, ferrules 26 aretypically of titanium. While being biocompatible and biostable, titaniumtends to form oxides on its surface. Such an oxide layer 506 is shown inFIG. 27B. It would be appreciated that these oxide layers 506 wouldappear on all the surfaces of the titanium ferrule but are shown only onthe device side ferrule surface 26′ for convenience. This oxide layer506 can be present at the time electrical connection material 504 isapplied or it could occur later, particularly during laser welding 116of the ferrule 26 to the AIMD casing 32 or casing halves 112, 114. Whenconducting a laser weld 116, 116′, substantial localized heat may begenerated, which can accelerate oxide layer 508 formation.

It is generally believed that oxide layer 506 will not form on titaniumcomponents internal the AIMD casing 32 once hermetically sealed, mostlybecause AIMDs 12 can be assembled in or back-filled with an inert gas,such as helium, nitrogen or argon with the intent of inhibitingoxidation of sensitive metals like titanium. This belief is erroneous.Materials of construction used in the manufacture of AIMDs, such aspolymers, plastics, adhesives, elastomers and the like, and even theprinted circuit boards (PCBs) themselves, generally have some level ofgases trapped within their structure, for example, moisture, oxygen,other oxygen-containing gases, or even undetected residues comprisingsame, that eventually outgas during the operating life of the device.Furthermore, processes that could involve increased temperature likewelding, curing or other temperature shifts are possible during shippingand can accelerate such outgassing. Hence, even if an AIMD ismanufactured in an inert gas environment, or backfilled with an inertgas, such ‘heating’ of certain materials of construction can releaseoxygen, oxygen-containing gases or water vapor into an otherwisehermetically sealed environment causing the formation of oxide layers506 on conductive surfaces. The formation of this oxide layer 506increases the RF ground impedance, which does seriously degrade EMIfilter performance. This is why, during EMI filter initial designqualification (the EMI filters comprising a feedthrough filter 24, 24′,an MLCC capacitor 154, an X2Y attenuator 300, a flat-thru capacitor 400,and combinations thereof), the filter performance metrics at pre- andpost-AIMD casing 32 laser welding 116, 116′ should be recorded to besure there is no filter performance degradation. These filterperformance metrics must include: Equivalent Series Resistance (ESR)above 10 MHz and, in particular, at 64 MHz (MRI RF pulsed frequency of a1.5 T scanner), and insertion loss (IL) sweeps in dB on a networkanalyzer from 10 MHz to 3000 MHz, including 64 MHz (1.5 T MRI scanner)and 128 MHz (3 T MRI scanner). For more detail referring the effects ofoxide layer formation on EMI filtering, refer to the paper entitled,“Dissipation Factor Testing is inadequate for Medical Implant EMIFilters and Other High Frequency MLC Capacitor Applications”, ISSN:0887-7491, presented at CARTS 2003: 23rd Capacitor and ResistorTechnology Symposium, Mar. 31-Apr. 3, 2003, incorporated herein by thisreference. In summary, the presence of an oxide layer 506 can seriouslydegrade EMI filter performance (in dB), particularly at high frequenciesor at MRI RF-pulsed frequencies where the diverter filters must conducta substantial amount of high frequency current. Accordingly, theinventors have found that an electrical ground connection, such asillustrated in FIG. 27B, is a highly undesirable approach.

FIG. 27C and FIG. 27D are taken from sections 27C-27C and 27D-27D ofFIG. 27. FIG. 27C illustrates that the ferrule device side surface 26′has been cleaned of the oxide layer 506. Such an oxide layer 506 maycomprise several layers, with any one or more layers further comprisingone or more titanium oxide compositions. As mentioned, these oxidelayers 506 are undesirably insulative and can also cause potentiallyundesirable semi-conductor behavior. One approach that the inventorshave tried in the past is to clean the oxide layers 506 from the ferruledevice side surface 26′ using abrasive mechanical and chemical removalprocesses, including grit-blasting, mechanical grinding, sanding, andhydrofluoric acid cleaning. It should be noted that titanium oxides,once formed, are very stable and very hard to remove. Titanium oxidesare so stable that they are commonly used as paint pigments. Referringonce again to FIG. 27C, the inventors first cleaned the oxide layers 506from the device side ferrule surface 26′ and then formed a stripe or acoating of an electrically conductive adhesive (ECA stripe 514). The ECAstripe 514 may comprise a thermal-setting conductive epoxy, athermal-setting elastomer or a thermal-setting conductive polyamide. Theinventors then connected the edge metallization 500 of feedthroughfilter capacitors 24 directly to the ECA stripe 514 with electricalconnection material 504. This seemed to work very well in high frequencyelectrical measurements, including insertion loss (IL), impedance, ESRand inductance, all initially measuring very low and within acceptablespecification limits. However, out of a thousand pieces of prototypepieces evaluated, two exhibited higher impedances and were worrisome.

FIG. 27D is taken from section 27D-27D of FIG. 27, which illustrates incross-section the AIMD casing halves 112, 114 and laser weld 116 toferrule 26. It is generally understood that titanium has two propertiesthat greatly influence its weldabilty: 1) titanium has a great chemicalaffinity for combining with oxygen; and 2) titanium doesn't have a greataffinity for combining with any other chemicals. It is generallyunderstood that, in open air, freshly machined or cleaned titaniumquickly forms a layer of oxides. This formation of oxides creates anatural passivity that inhibits the reactions with other chemicals, suchas salt or oxidizing acid solutions. The result is that titanium hassuperior corrosion resistance. However, when heated during welding,these oxides form even faster, and as the temperature reaches titanium'smelting point (1668° C., 3034° F.), the oxides dissolve into solutionand contaminate the weld pool, causing an impure and very weak weld. Forthis reason, special care is generally taken to minimize exposure of thetitanium pieces to oxygen during welding. Hence, AIMD 12 manufacturingprocesses typically employ a shield gas such as argon or helium.Titanium can also be reliably welded in a full vacuum (as is the casewith electron beam welding). Regardless, laser welding can cause heatingalong the weld seam, which may also involve heating of the device sideferrule surface 26′. Hence, it is conceivable that when exposed to suchheating from laser welding, the titanium ferrule 26, and in particularthe device side ferrule surface 26′, can undesirably re-oxide. Theinventors studied the effect of such protective laser welding onfeedthrough filters, measuring ESR/IL pre- and post-laser welding. Theinventors observed that post-laser welding, the ESR measurements of somefeedthrough filters 24 of a very large lot increased from the pre-laserwelding measurement by orders of magnitude. To this day, when attachmentis made directly to titanium or other oxidizable metal without thepresence of an oxide-resistant intermediary between the titanium and theelectrical attachment material, the inventors have found that, whilemost parts in a 1000 piece production lot remain within ESR/ILspecification post-laser welding 116. There are consistently some partsin the same lot that fail ESR/IL horribly. Thus, since failing ESRmeasurements remain unpredictable even under protective laser weldingprotocols, attaching to an ECA stripe 514, as illustrated in FIG. 27C,is a highly undesirable practice. Accordingly, the generally acceptedbelief that oxide layer 506 will not form on titanium componentsinternal the AIMD casing 32 once hermetically sealed, simply becauseAIMDs 12 can be assembled in or back-filled with an inert gas ascommonly thought for inhibition of oxidation of sensitive metals liketitanium is flawed and inaccurate.

In summary, the deposition of an ECA stripe 514 proved to be a highlyunreliable electrical connection, which is prone to increasing inresistance, whether occurring over time or when exposed to laser weldingduring installation into an AIMD casing even when a shield gas is usedor if the laser weld is made in full vacuum.

Referring once again to FIGS. 27C and 27D, the inventors have conceiveda novel concept by which the ECA stripe 514 can be effective. To renderthe ECA stripe 514 effective, a low resistance and low impedanceconnection at high frequencies must be made. To achieve such a lowresistance and low impedance connection, especially for highfrequencies, two very important steps are required: Step 1) at least theferrule side device surface 26′ must be cleaned of all oxides; and, Step2) an oxide-resistant layer 516, as shown in FIG. 27H, must be disposedon the ferrule surface device side 26′ at least in the area of the ECAstripe 514. As described previously, cleaning of the ferrule device sidesurface 26′ can be done mechanically or chemically by either abrasivegrit blasting, such as by alumina blasting, mechanical grinding, sandingprocesses, hydrofluoric acid cleaning, or combinations thereof, whichwould remove oxide layers 506 from the ferrule 26, or at least theferrule device side surface 26′. Once the ferrule 26, and in particular,its device side top surface 26′ have been essentially cleaned of oxides,time becomes important. If the cleaned ferrule is left lying around atroom temperatures, or worse yet, exposed to elevated temperatures,intentionally or unintentionally, these oxides will undesirably re-form.Accordingly, the inventors have tested and determined that anoxide-resistant layer 516, such as a noble metal layer must be depositedsoon after at least the ferrule device side surface 26′ Is cleaned ofoxides. One preferred method of depositing an oxide resistant layer 516on the ferrule device side surface 26′ includes sputtering, includingsputtering of such materials as gold, platinum, rhodium, or palladium.Other ways of disposing an oxide-resistant layer would be by physicalvapor deposition, chemical vapor deposition, electrostatic sprayassisted vapor deposition (ESAVD), electron beam physical vapordeposition (EBPVD), ion plating, ion beam assisted deposition (IBAD),magnetron sputtering, pulsed laser deposition, sputter deposition,vacuum deposition, pulsed electron deposition (PED), plating,electroless plating, electroplating, spraying, painting, plasmaspraying, thermal spraying, spin coating, dip coating, metal foillamination, and thin film deposited layers, either fully or selectivelydisposed. The electrically conductive coating may comprise one or morelayers. These processes may be used to deposit materials such as gold,gold alloys, rhodium, rhodium alloys, platinum, platinum alloys,platinum-iridium alloys, palladium, palladium alloys, nitinol,cobalt-chromium alloys and combinations thereof. Additionally, selectiveelectro-plating can be used. For example, a layer of nickel would firstbe deposited on top of the essentially oxide-free titanium surface atleast in the area of where the ECA stripe 514 is intended to bedeposited on the ferrule surface device side 26′. Then, an oxideresistant layer 516, such as a layer of gold, platinum, rhodium, or anyof the materials disclosed above, would be plated on top of an optionalnickel layer. The purpose of the nickel layer is to prevent titaniumfrom migrating through an oxide-resistant layer. For example, even athin film gold layer is highly resistant to forming oxides and is highlyconductive. However, a thin film gold layer may be relatively “porous”,which could allow titanium to migrate through the thin film gold layerto its free surface. Researchers have shown that, when a thin film goldlayer is disposed on an essentially oxide-free titanium surface, thetitanium can diffuse along the grain boundaries at the gold/titaniuminterface to the free surface of the thin film gold layer, where thetitanium is oxidized. Accordingly, laying down a layer of nickel orother suitable material that prevents migration of titanium through it,would be required. In another embodiment, the nickel layer could beomitted with a suitably thick layer of gold, platinum or the like, suchthat they sustain oxide resistance.

FIG. 27E is taken from section 27E-27E of FIG. 27 and illustrates analternative embodiment that also provides a very reliable low impedanceelectrical connection. Shown, is an EMI filter circuit board 106′ of thepresent invention with a ground via hole 512. The ground via hole 512 isspatially aligned over an oxide-resistant pocket pad 508. Gold pocketpads are disclosed in U.S. Pat. No. 10,350,421, the contents of whichare fully incorporated herein by this reference; however, pocket padsmay comprise other oxide-resistant materials such as platinum. Noblemetals, such as gold and platinum, are used as jewelry for this reason,as gold and platinum do not tarnish or oxidize over time. The pocket pad508 may comprise a number of oxide-resistant materials, such as gold,gold alloys, rhodium, rhodium alloys, platinum, platinum alloys,platinum-iridium alloys, palladium, palladium alloys, nitinol,cobalt-chromium alloys and combinations thereof. In the case of a goldpocket pad, co-brazing the pocket pad 508 at the same time that the AIMDhermetically sealed feedthrough 14 is formed saves time and is veryefficient. As such, a low impedance and low resistance electricalconnection to the ferrule 26 may be formed from the ferrule through thegold pocket pad 508 to the electrical connection material 504 and then,in turn, to the EMI filter circuit board 106′ edge metallization 500.Only a few oxide-resistant pocket pads 508 need be disposed on thedevice side ferrule surface 26′ to provide for a very low resistance andlow impedance electrical connection. During machining or formation ofthe ferrule 26, the oxide-resistant pocket pads 508 can be formed assmall circles or rectangles. They do not need to be very deep.Accordingly, they can be made of thin gold preforms, which arerelatively inexpensive.

FIG. 27F is taken from section 27F-27F of FIG. 27. In a similar mannerto FIG. 27E, the EMI filter circuit board 106′ illustrates a via hole512. In FIG. 27F, however, instead of the via hole 512 being spatiallyaligned to an oxide-resistant pocket pad, the via hole 512 is spatiallyaligned over the braze material 46 a, which is a gold braze thatprovides a robust mechanical connection between the ferrule 26 and theinsulator 28 of the AIMD hermetically sealed feedthrough 14. Electricalconnection material 504 residing in the via hole 512 connects the viahole metallization 510, which is electrically connected to the one ormore ground plates 156 and to the braze material 46 a. This forms areliable low resistance and low impedance electrical connection and astable ground path.

FIG. 27G is taken from section 27G-27G of FIG. 27 and illustrates thatthe oxide-resistant pocket pad 508 can also be used for electricalconnection to a circuit board edge metallization 500. In this case, asillustrated, the circuit board edge metallization 500 is connected usingelectrical connection material 504. The electrical connection material504 may comprise various solders and/or thermal-setting conductiveadhesives for connecting both the device side ferrule surface 26′ andthe gold pocket pad 508. It is not important that the electricalconnection material 504 make contact directly to the device side ferrulesurface 26′, but it is critical that the connection material 504 atleast partially contacts the oxide-resistant gold pocket pad 508.

FIG. 27H is similar to FIG. 27C, except that an oxide-resistant layer516 is shown in addition to the ECA stripe 514. The oxide-resistantlayer 516 may comprise one or more layers. As previously described,either a single oxide-resistant layer 516 may be used or a first layerof nickel and then a suitable oxide-resistant second layer 516, such asa second layer comprising gold, may be disposed over the first layer ofnickel (not shown), to achieve a low resistance and low impedanceelectrical connection between two AIMD components. Referring to the ECAstripe 514 of FIG. 27H, it is contemplated that, for some applicationswherein ECA electrical connection may not be needed to provide anelectrical connection between at least two AIMD components, the ECAstripe 514 could be eliminated if the oxide-resistant layer(s) 516is/are robust enough to prevent titanium migration and oxidation,thereby allowing attachment of the electrical connection material 504directly to the oxide-resistant layer 516. In other words, either anoxide-resistant layer(s) could be used to make the ECA stripe 514 aneffective low resistance and low impedance connection or theoxide-resistant layer(s) alone can be used instead of the ECA stripe514. It will be appreciated that the ECA stripe 514 and/or themetalization layer 516 may also be used to provide suitable grounding,not just for circuit boards 106, 106′, but also for all types of filtercapacitors, including feedthrough filters 24, 24′, hybrid feedthroughcapacitors 24″, MLCC capacitors 154, X2Y attenuators 300, and flat-thrucapacitors 400.

The ECA stripe 514 over an oxide-resistant layer 516, or anoxide-resistant layer 516 without the ECA stripe 514, can beelectrically connected directly to a ground edge metallization or atleast one ground via hole of any of a flat-thru shielded circuit boardfilter as taught and disclosed in U.S. Pat. No. 8,195,295, the contentsof which are fully incorporated herein by this reference.

Thus, the ECA stripe 514 disposed directly atop the ferrule device sidesurface 26′, which was subjected to substantial testing, does notprovide a reliable, low resistance connection. The inventors have testedECA stripe 514 after laser welding, and after high reliability testing,including burn-in and life testing at elevated temperatures. In all testcases, some percentage of the devices had an undesirable increase in theESR of the EMI filter and a reduced filter performance. Disposing one ormore oxide-resistant layers 516 atop the ferrule device side surface26′, with or without an ECA stripe 514, results in a reliable lowresistance and low impedance electrical connection, including a lowresistance and low impedance ground connection for various types offilter capacitors: feedthrough filters 24, 24′, hybrid feedthroughcapacitors 24″, MLCC capacitors 154, X2Y attenuators 300, flat-thrucapacitors 400, and the flat-thru EMI filter circuit boards taught bythe '295 patent.

Referring once again to FIGS. 27 and 27A, it is important that theterminal pin 18 gnd be of suitable oxide resistant material, such asrhodium, rhodium alloys, platinum, platinum alloys, platinum-iridiumalloys, palladium, palladium alloys, nitinol, cobalt-chromium alloys andcombinations thereof. This is so that terminal pin 18 gnd can either belaser welded or gold brazed to the ferrule 26, thereby providing anoxide-resistant structure for electrical connection material 504 so thata low resistance and low impedance electrical connection is made to theEMI filter circuit board 106′ and the ferrule 26.

Referring to FIG. 27A, the ground terminal pin 18 gnd could be laserwelded anywhere on the device side ferrule surface 26′ or the edge ofthe ferrule 28 (not shown). What is important is that the terminal pin18 gnd makes a low resistance metallurgical connection and is itselfoxide-resistant, which means essentially oxide-free, to the ferrule 26and also at the same time, provides for an oxide resistant surface towhich circuit boards or EMI filters connect.

Referring to FIGS. 27, 27A-27H, the embodiments comprising connection toan oxide-resistant layer 516 as shown FIGS. 27, 27A, 27E, 27F, 27G and27H are preferred. The embodiments illustrated in FIGS. 27B, 27C and27D, which do not comprise an oxide-resistant layer 516, are allundesirable attachment configurations that ultimately result inunreliable electrical connections prone to oxidation and increases inresistance and RF impedance over time (particularly when exposed toelevated temperatures).

FIG. 28 is taken from section 28-28 of FIG. 27 illustrating the top viewof the EMI filter circuit board 106′ disposed at, near or distant fromthe ferrule 26. In this case, each one of the capacitors 154 a-154 f isdirectly connected either through a circuit trace 162, as shown, or adirect solder connection or thermal-setting conductive adhesiveconnection or the like, from the MLCC 154 active electrode plates toeach of the six active terminal pins 18. The ground electrode plates ofthe MLCC's 154 are connected to via holes which communicate with the atleast one internal ground electrode plate 156 of the EMI filter circuitboard 106′. In this way, the capacitors are connected both to the activepins and to the effective RF ground, which diverts unwanted highfrequency energy from the terminal pins 18 through the filter capacitorto the ground plate and in turn, to the ferrule 26 and then to the AIMDcasing 32, which together acts as an overall Faraday shield. ThisFaraday shield prevents the EMI from entering the AIMD casing 32 andinstead causes the dangerous unwanted EMI RF energy to circulateharmlessly as eddy currents in the AIMD casing 32 without penetratinginside the AIMD casing where it could undesirably couple to sensitiveAIMD circuitry and cause AIMD malfunction. It is noted herein thatcertain AIMD malfunctions can be life-threatening to a patient.

Referring once again to FIG. 28, one can see that each of the MLCCs 154are grounded to a via hole or a circuit trace labeled gnd a-gnd f. Thesevia holes are disposed through the circuit board and contact at leastone ground electrode plate 156, which as previously described, isconnected to the ferrule 26, thereby, providing a low impedance RFground.

Referring once again to FIG. 28, the exemplary circuit traces 162 onlyshow one embodiment, in this case, for MLCCs 154. It is contemplatedthat, for the X2Y attenuators 300, the circuit traces would be modifiedto make at least two active connections to the X2Y attenuator, whichwould then have at least one ground connection. For example, MLCCs 154could also be replaced by flat-thru capacitors 400. In this case, thecircuit traces would be different, in that, there would be a thirdterminal connected to the flat-thru capacitors 400, which would begrounded, and the circuit trace currents would go through the flat-thrucapacitor. Such flat-thru capacitors are all more thoroughly disclosedin U.S. Pat. No. 10,272,252, which is incorporated herein by reference.

FIG. 28A is an isometric view of a prior art surface mounted capacitorthat is also known by those skilled in the art as an X2Y attenuator 300.The X2Y attenuator was originally invented by the X2Y Attenuator®company. The X2Y attenuators are sold by Knowles/Syfer® and theKnowles/Syfer online catalogs are publicly accessible. In addition, theX2Y Attenuator company has approximately 72 patents assigned to them,some of which have been licensed to Knowles/Syfer. There are manyvariations to the X2Y attenuator 300 and only one embodiment is shownherein (see FIG. 28A). FIG. 28C illustrates how X2Y attenuator 300 canbe attached to the EMI filter circuit board 106′ of the presentapplication. It will be understood by one skilled in the art thatvariations of the X2Y attenuators, including those described in the X2Ypatents, could be used by adjusting the circuit board 106′ circuittraces and the related physical embodiments disclosed herein. X2Yattenuators are so well known in the prior art that the inventors havenot described all of the variations and shapes that are possible so asnot to obfuscate the present application.

Referring once again to FIG. 28A, illustrated is an X2Y attenuator 300having a dielectric body 314 comprising metallized terminations 301 and302. As will be further described, the metallized terminations 301 and302 are electrically conductive and solderable and will also accept athermal-setting conductive adhesive such that these metallizedterminations 301 and 302 can be connected to terminal pins 18, 18 gnd orto circuit traces 418, 418 gnd. Referring once again to FIG. 28A, onewill see that there is a ground termination 304, as shown. This groundtermination 304 of FIG. 28A comprises a continuous metallization bandcentrally located all of the way around the surface mounted X2Yattenuator, however, it is appreciated that the ground metallization 304about the surface mounted X2Y attenuator could also be discontinuous. Aground connection 306 is made such that electromagnetic interference(EMI) signals from conductors attached to the metallized terminations301 and 302 can be capacitively decoupled at the ground connection 306to a system ground (not shown), which, for an AIMD application, cancomprise the ferrule 26 or the flange 30 of the ferrule 26, which isdesigned to be electrically connected to the overall AIMD casing 32 ofthe AIMD 12. As previously disclosed, this overall AIMD casing 32 addsan electromagnetic shield or Faraday cage to which undesirablehigh-frequency EMI signals may be diverted or decoupled (filtered).

FIG. 28B is taken from section 28B-28B of FIG. 28A. The sectionsillustrated in FIG. 28B represent different depths of the X2Y attenuatorof FIG. 28A showing various layers through section 28B-28B. Referringback to FIG. 28A, the X2Y attenuator 300 has a dielectric body 314 asindicated. The dielectric body 314 may be a ceramic dielectric, such asa barium titanate, a strontium titanate or the like. In low capacitancevalues, the dielectric body 314 could even be an alumina ceramic or anytype of ceramic structure. The dielectric body 314 may also comprisevarious insulative films, such as mylar (otherwise known as a stack-fillcapacitor), Kapton® or many other types of film capacitors. It will alsobe appreciated that the dielectric body 314 could comprise a tantalumcapacitor or an electrolytic capacitor. Referring now to FIG. 28B, onecan see the active electrode plate 308 in the illustration at the top ofFIG. 28B is associated with capacitance area Ca. The active electrodeplate 308 is a conductive layer, which is connected to the metallizedtermination 301. The conductive layer shown in the middle illustrationof FIG. 28B is a ground electrode plate 310 configured to be connectedto the metallization termination 304. It is noted herein that themetallization terminations 304 and 306 of the X2Y attenuator of FIG. 28Acan be continuous as shown or discontinuous (not shown). The conductivelayer shown at the bottom of FIG. 28B is an active electrode plate 312,which is connected to metallization termination 302 and is associatedwith capacitance area Cb. It is the overlap of the active electrodeplate 308 with ground electrode plate 310 that forms the capacitance Ca.Likewise, it is the overlap of active electrode plate 312 with theground electrode plate 310 that forms the capacitance Cb. As will beshown, by selectively eliminating the ground electrode plate, anelectrode plate stack up may comprise ten, twenty, thirty or evenhundreds of conductive layers. In so doing, one can form and/or tailor acapacitance between the capacitance Ca and the capacitance Cb. FIG. 28Bpresently illustrates a ground electrode plate 310 thatelectrostatically shields the capacitance area Ca of the activeelectrode plate 308 from the capacitance area Cb of the active electrodeplate 312. Therefore, the line-to-line capacitance Ca-b would betrivially small. So, it is only when one selectively removes the groundelectrode plate 310, that one achieves a high effective capacitance areabetween active electrode plates 308 and 312 such that significantline-to-line capacitance will be achieved.

FIG. 28C is a top view of the device side of the EMI filter circuitboard 106′ showing a more common version of the X2Y attenuator 300,previously described in FIG. 28A, previously described in FIGS. 27 and28. The X2Y attenuator 300, illustrated in FIG. 28C, is electricallyattached by its left-hand side active metallization termination 301 andelectrical attachment material 58 to active terminal pin 18 a. On theright-hand side of the X2Y attenuator 300, the active metallizationtermination 302 is electrically connected to active terminal pin 18 b.The specific type of electrical connection is not important as it mayencompass a circuit trace (not shown), a circuit trace landing pad (notshown), direct connection to vias/via holes (only partially shown), orplated or metallized vias. Referring once again to FIG. 28C, one can seethe ground metallization termination 304 of the X2Y attenuator 300. Inorder to provide very low impedance RF grounding, the groundmetallization termination 304 has been electrically connected to twogrounded via holes gnd a,b and gnd a′,b′. Short circuit traces 418 areshown between the ground via holes and the ground metallizationtermination 304 of the X2Y attenuator 300. These circuit traces 418 maybe long or may be eliminated simply by moving the ground via holescloser to the capacitor ground metallization termination 304 such that adirect connection can be made to the via holes. Such a change to theactive traces can similarly be made.

Now referring to FIG. 28D, illustrated is a schematic of the X2Yattenuators 300 previously described in FIGS. 28A, 28B and 28C. One cansee that capacitances Ca and Cb are both connected to ground 26, 30.Ground 26, 30 is a ground to the ferrule 26, which becomes the systemground once the ferrule is welded to the AIMD casing 32. Referring onceagain to FIG. 28D, a line-to-line capacitance Ca-b may be formed betweenterminal pins 18 a and 18 b. As previously described in FIG. 28B, thisline-to-line capacitance Ca-b would be made by selective elimination ofground electrode plates 310 such that an effective capacitance area(ECA) develops between Ca and Cb. It is noted herein that not all of theground electrode plates 310 can be removed. If this were the case, thenCa and Cb capacitance would not even exist Therefore, ground electrodeplates 310 may only judiciously removed selectively. To EMI specialists,such judicious elimination of ground electrode plates is known asbalancing the common mode filter attenuation with the differential modefilter attenuation. Differential mode means a differential signalbetween terminal pins 18 a and 18 b. This is understood more simply ifone was to put a high-frequency volt meter between terminal pins 18 aand 18 b, where one would read a voltage. The purpose of capacitanceCa-b is to divert the voltage so that the voltage cannot get into theinside the AIMD 12. This is called differential mode filter attenuation.Referring once again to FIG. 28D, capacitances Ca and Cb are shown bothconnected to ground 26, 30. Because they are both connected to a commonpoint, this means they are also connected to each other as the schematicillustrates. The schematic, however, could be changed so that Ca and Cbare separated, with each connected to a ground symbol. It will beunderstood that such a connection is the same thing. This configurationis to protect against differential mode EMI. This is also easy tounderstand if one were to take a volt meter, say, on terminal pin 18 aand place it between the terminal pin and the ferrule and one measured ahigh-frequency AC voltage, then the purpose of capacitance Ca is toattenuate or divert that differential mode EMI to the ferrule so thatdangerous EMI will not enter into terminal pin 18 a into the inside ofthe AIMD 12 where the EMI could therefore disrupt the proper operationof the electronic circuits of the AIMD.

FIG. 28E is known in the prior art as a flat-thru capacitor 400. Thisterm was coined by one of the inventors, Robert A. Stevenson, when hewas working on his master's thesis. This term also appears in a numberof patents, including U.S. Pat. No. 8,195,295. This type of capacitor isunique in that circuit current actually passes through the electrodes ofthe capacitor itself. These capacitors are also commonly known in theprior art and are public sold online, including online catalogs for samethat are also publicly accessible.

Referring once again to FIG. 28E, one can see that the flat-thrucapacitor 400 is similar to the X2Y attenuator 300 in that a firstactive metallization termination 402 and a second active metallizationtermination 406 resides at both ends of the flat-thru capacitor 400. Theflat-thru capacitor 400 also has ground metallization terminations 404and 404′. The ground metallization termination, in this case, 404 and404′ is shown discontinuous, but like for the X2Y attenuator, it iscontemplated that this termination 404 and 404′ could comprise acontinuous band all the way around the capacitor, as illustrated for theX2Y attenuator of FIG. 28A. Current 410, i₁ is shown entering in from acircuit trace 418 to a circuit board landing pad 416 to which themetallization termination 402 is electrically connected using electricalconnection material 420. The electrical connection material 420 isbetter shown on the right-hand side of the flat-thru capacitor 400 wherethe metallization termination 406 is electrically connected to circuitboard landing pad 416′. The current 410, i₁ is conducted all the waythrough the capacitor very much like a feedthrough capacitor, except inthis case as will be shown, the current passes through the capacitor'selectrode plates. This makes the flat-thru capacitor very unique in theprior art. The circuit current 410, i₁, passes through the capacitorthen exits on the right-hand side as the same circuit current 410′, i,this time from circuit trace 418′.

FIG. 28F is taken generally from section 28F-28F of FIG. 28E. One willappreciate that electrode plate 412, when building a monolithic ceramiccapacitor structure 408, have to be thin and lacey, so the structuredoes not de-laminate and remains monolithic. As used herein, the term“lacey,” as it refers to an electrode plate, means that, instead ofbeing a solid thick metal sheet, the electrode plate has a plurality ofopen spaces through its thickness (more like a window screen) throughwhich grain growth can infuse and traverse the bulk ceramic dielectricduring sintering. The distribution of open spaces doesn't have to behomogeneous like a window screen, but there does have to be sufficientamount of open space areas in the electrode plate so that duringsintering, the grain growth of the bulk ceramic dielectric willpenetrate through the electrode such that the entire capacitor anchoringthe electrode plate to the bulk ceramic thereby forming a truly solidand monolithic conductive layer. This is in contrast to a bolognasandwich analogy, where the layers of bread and bologna easily separateand delaminate or otherwise are taken apart one from the other. For moreinformation on delamination one is referred to the paper entitled “DUALELECTRODE PLATE MLCC FOR HIGH VOLTAGE PULSE APPLICATIONS” presented atthe Capacitor and Resistor Technology Symposium held on Mar. 6-10, 2000at Huntington Beach, Calif., (ISSN 0887-7491), the contents of which arefully incorporated herein by this reference.

Electrode plate 412 is the active electrode plate through which thecircuit current 410, i₁ passes all the way through. Therefore, it isdesirable that there be a relatively high number of active electrodeplates 412 stacked up in interleaved relationship such that sufficientcross-sectional area exists to thereby preclude a high resistance to theflow of the current 410, i₁. It is also desirable that active electrodeplats 412 be relatively wide (possibly much wider than shown) such thatthe circuit current 410, i₁ does not encounter excessive resistance orinductance. Actually, in the case of FIG. 28F, the inductance of theelectrode plates 412 is desirable in that the inductance is in serieswith the electromagnetic filtering of the flat-thru capacitor 400. As iswell known to EMI engineers, series inductance can help reduce theamount of electromagnetic energy that can get inside of a structure, inthis case, the AIMD casing 32. The inductance L,422 of the embodiment ofFIG. 28F is therefore highly desirable. Normally, for prior artfeedthrough capacitors and MLCCs, an inductance is undesirable, as theinductance, as shown in the schematic of FIG. 28G, would be in seriesbetween the capacitance and ground thereby degrading filter performanceat high frequencies. However, in the case of FIG. 27E, as will be shown,the inductance shows up in series with the terminal pin, thereby,providing increasing inductive reactance at high frequencies whichconsequently improves filter performance.

Referring again to FIG. 28F, one can see the ground electrode plate 414that is connected to the ground metalization terminations 404 and 404′.As previously disclosed, such ground metallization terminations areconfigured to be attached to a system ground, which is the AIMD casing32.

FIG. 28G is the schematic of the prior art flat-thru capacitor 400. Theflat-thru geometry has an enormous advantage in that, any stray orparasitic inductance of the electrode plates shows up in series with theterminal pin 18 (18 a). As previously described, this series inductancehelps to attenuate undesirable EMI. The flat-thru capacitor 400 isgrounded through the ground symbol to the ferrule 26 and in turn, tosystem ground (namely, the AIMD casing 32), as previously disclosed. Adeficiency of the flat-thru capacitor is also illustrated in FIG. 28G.That is, at extremely high frequency, EMI can couple (radiate) throughthe air between metallization terminations 402 and 406, or worse yet,from circuit trace 418 to circuit trace 418′. EMI cross-coupling dependson the geometry of the circuit, the spacing and size of the circuittraces and the size of the flat-thru capacitor, but, in general, suchundesirable EMI cross-coupling does not happen until one is in the GHzfrequency range, such as 3 GHz. Fortunately, the human body effectivelyabsorbs and reflects EMI in the GHz region, particularly above 3 GHz,such that it is very difficult for extremely high frequency energy topenetrate very far inside the human body. Accordingly, the flat-thrucapacitor 400 is an acceptable EMI filter tradeoff for use in activeimplantable medical devices that are designed to be placed inside thehuman body with leadwires also disposed inside the human body. The humanskin, muscle and fats tend to reflect and absorb such extremely highenergy, thereby compensating for the flat-thru capacitor's tendency forEMI to couple across the flat-thru capacitor 400.

FIG. 28H is very similar to FIGS. 28 and 28C in that, the embodiment ofFIG. H shows the top view of the device side of an EMI filter circuitboard 106′, comprising three flat-thru capacitors mounted to the topsurface of the EMI filter circuit board 106′. One can see flat-thrucapacitor 400 disposed between terminal pins 18 a and 18 a′. Circuitcurrent enters terminal pin 18 a as undesirable EMI energy from the bodyfluid side (not shown) up to the top of terminal pin 18 a and then thecircuit current passes through the capacitor body of the flat-thrucapacitor 400 to terminal pin 18 a′ and is then directed to the circuitboard active electronic circuits of an AIMD active electronic circuitboard 106. Metalization termination 402 is electrically connected withelectrical connection material 420, such as a solder or athermal-setting conductive adhesive to circuit via hole 18 a. Thiselectrical connection may comprise a circuit board landing pad, acircuit board trace or even internal circuit board traces (not shown).There are many ways to make an electrical connection between theflat-thru capacitor's metalization terminations 402 and 406 to thecorresponding leads 18 a and 18 a′ thereby electrically connecting tothe metallization terminations. The ground electrode plates 414 of theflat-thru capacitor 400 are electrically connected to ground vias gnd aand gnd a′. In the embodiment of FIG. 28H, there are short circuittraces shown, but as previously described for the X2Y attenuator, theseshort circuit traces are not necessary as the via holes gnd a and gnd a′could be moved immediately adjacent the metallization terminations 404and 404′ such that a direct electrical connection is made to the viaholes gnd a and gnd a′. In addition, ground vias gnd a and gnd a′ couldeven comprise a single bump underneath the flat-thru capacitor 400wherein a robotic dispenser could accurately place a BGA dots such thatthe ground electrical connection would be invisible beneath theflat-thru capacitor 400. Those skilled in the art will appreciate thatthere are many possible ways to make the electrical connections to theflat-thru capacitor 400. BGA dots can alternatively be solder bumps ordots of a conductive thermal-setting adhesive.

FIG. 28I is a sectional view taken from section 28I-28I of FIG. 28H. Theembodiment of FIG. 28I illustrates terminal pin 18 a passing through theinsulator 28 of an AIMD hermetically sealed feedthrough 14 and a via ofan EMI filter circuit board 106′ and electrically connected to theflat-thru capacitor 400 left-hand side active metallization termination402. Terminal pin 18 a must be discontinuous of terminal pin 18 a′because, for the flat-thru capacitor 400 to function such that unwantedhigh frequency electrical interference is effectively diverted, thecircuit current h,410 must pass right through the electrode plates ofthe flat-thru capacitor 400. Accordingly, on the right-hand side of theflat-thru capacitor 400, the active metallization termination 406 iselectrically connected to terminal pin 18 a′. As previously discussed,terminal pin 18 a could be disposed in an EMI filter circuit board 106′via hole 109. So as one traces the circuit current i₁, 410, from thebody fluid side, one will appreciate that the circuit current i₁, 410,if it is a low frequency or DC current, low frequency meaning lowfrequency biologic signals, or low frequency therapeutic pacing pulses,such as cardiac pacing pulses, would pass from the body fluid side orfrom the device side from terminal pin 18 a through the active electrodeplates 412 of the flat-thru capacitor 400 and in turn, to the deviceside terminal pin 18 a′ as i₁, 410′.

Further regarding the embodiment of FIG. 28I, the terminal pinconnectors 16 on the device side of the embodiment illustrated in FIG.28I are attached to circuit board lands on an AIMD active electroniccircuit board 108 (not shown). If therapeutic low frequency pulses flowthrough the circuitry of the AIMD active electronic circuit board 106with the intention of travelling to the distal electrodes in contactwith human tissue, then the therapeutic pacing pulses would come fromthe device side of the AIMD into terminal pin 18 a′ and would then flowthrough flat-thru capacitor 400 unattenuated, and then flow out throughterminal pin 18 a on the body fluid side of the AIMD, through the leads(not shown) connected on the body fluid side of the AIMD, to the distalelectrodes of the leads thereby stimulating a body tissue, for example,the myocardium of a heart. On the other hand, if terminal pin 18 a wasintended for sensing low frequency biologic signals, such low frequencybiological signals sensed by a distal electrode of a lead entersterminal pin 18 a on the body fluid side, then passes through theflat-thru capacitor 400 unattenuated or minimally attenuated, and thendesirably flows to terminal pin 18 a′ to a circuit board circuit traceof the AIMD active electronic circuit board 106 (not shown). The sensesignal would be assessed, and stimulation therapy appropriately adjustedsuch that the adjusted therapeutic low frequency pulses can flow throughthe circuitry of the AIMD active electronic circuit board 106,travelling the original therapy delivery path disclosed above.

There is a third type of signal that is very important and that is ahigh frequency dangerous EMI signal. If that signal is picked up by thebody fluid side leads and distal electrodes, the undesirable EMI currentwould enter into terminal pin 18 a, on the body fluid side and thenwould pass through the active electrode plates 412 of the flat-thrucapacitor 400. Ideally, the flat-thru capacitor would divert (orcapacitively decouple) this dangerous high frequency EMI energy throughthe capacitive reactance of the flat-thru capacitor 400 to the ferrule26 and then, in turn, to the AIMD casing 32, which acts as a Faradaycage. In this way, the flat-thru capacitor 400 allows low frequencypacing and biological sensing signals to freely pass, while attenuatingor filtering dangerous high frequency EMI.

FIG. 28J illustrates a different embodiment of a flat-thru capacitor400′ comprising four poles, which is known as a quad polar flat-thrucapacitor. Instead of a monopolar or one-pole flat-thru capacitor 400 asshown in FIGS. 28E-28I, FIG. 28J indicates that flat-through capacitorscould embody many poles in a monolithic dielectric body. Flat-thrucapacitors can have any number of poles in various geometricconfigurations. This is better understood by referring to FIG. 28K,where one can study the four active electrode plates 412 a through 412 dIllustrated. As disclosed for the monopolar flat-thru capacitor 400 ofFIGS. 28E-28I, the circuit current i₁ must pass through the four activeelectrode plates 412 a through 412 d as indicated for active electrodeplate 412 a, in an overlap relationship with ground electrode plates414. The metallization terminations 404 and 404′ would be connected tosystem ground (that is, to the ferrule 26 and in turn, to the AIMDcasing 32 not shown). The overlap of the active layers 412 a through 412d with the ground electrode plate 414 creates four flat-thrucapacitances. Flat-thru capacitors can greatly vary in geometry andshape and are similar to X2Y attenuators in that flat-thru capacitorscan also include 1, 2 or even “n” number of attenuators (poles) In amonolithic package.

FIG. 29 is very similar to FIG. 27, in that the EMI filter circuit board106′ has at least one ground electrode plate 156, which can be internalor external. However, in the embodiment of FIG. 29, the ground electrodeplate 156 is not grounded to a pin that is welded or brazed to theferrule 26. Instead, there is a circuit board metallized via hole thattraverses the at least one internal ground electrode plate 156 therebyis electrically connected to the at least one internal ground electrodeplate 156. The via hole is spatially aligned such that the via hole sitsat least partially atop the gold braze 46 a of the hermetic seal betweenthe insulator 28 and the ferrule 26. Illustrated is an electricalconnection material 158 gnd, which is disposed either filling the viahole or on the internal sidewall of the via hole traversing the at leastone internal ground electrode plate 156, thereby completing anelectrical connection from the ground electrode plate 156 (in this FIG.shown as an internal ground electrode plate) to the gold braze 46 a.Ground electrode plate 156 can be any number ‘n’ electrode groundplates, the ‘n’ ground electrode plates being either all internal groundplates or internal and external ground electrode plates. As previouslydisclosed herein, it is very important that the ground electricalconnection be to a ferrule 26 comprising an oxide resistant surface, oneembodiment shown previously in FIG. 27. An oxide-resistant surface mayfurther comprise an oxide-resistant (essentially oxide-free) groundterminal pin. In the case of FIG. 29, the ground via hole is spatiallyaligned atop gold braze 46 a, however, a plurality of via holes can bealigned strategically over the gold braze 46 a of the hermetic seal.Referring once again to FIG. 29, a ground via hole of the EMI circuitboard 106′, may comprise an electrical connection comprising anelectrically conductive solid filled via hole, the electricallyconductive solid filled via hole comprising a BGA, a solder, a solderbump, a conductive epoxy, a conductive epoxy bump or an anisotropicconductive film (ACF). It is contemplated that many of the electricalconnections disclosed herein can also alternatively be used. One is alsoreferred to FIGS. 92 and 93 of U.S. Pat. No. 8,195,295, whichillustrates a circuit board (192) having internal ground electrodeplates (194) and (194′) grounded through via holes directly connected tothe gold braze (124) of a hermetic seal. As previously noted, theelement numbers in parenthesis are the element numbers of the '295patent. One is also referred to FIG. 94 of the '295 patent for anotherexample of a solid filled via hole and electrical connection material(260) that makes contact with the hermetic seal gold braze (124). One isalso referred to FIGS. 95, 96 and 97 of the '295 patent for examples of(196) pins or structures (270) over which a circuit board ground via canbe placed and electrically attached. U.S. Pat. No. 8,195,295 is fullyincorporated herein by this reference.

FIG. 30 illustrates an exemplary embodiment of a bus-bar-like terminalpin connector for providing electrical connection between one or morecomponents of the AIMD and one or more feedthrough conductive pathways,wherein the one or more feedthrough conductive pathways are selectedfrom the group consisting of a terminal pin, a pin, a leadwire, a leadwire, a two-part pin, a lead conductor, a sintered paste-filled via, aco-sintered via, a co-sintered via with one or more metallic inserts, orcombinations thereof, and wherein the component of the AIMD comprisesone of a circuit, a circuit board, an electrical component, a header, aheader block, or combinations thereof. The embodiment of FIG. 30simulates a bus-bar in that the embodiment shown is capable of providingmultiple feedthrough conductive pathway connections uses a single topcapture pad 172 capable of capturing a group of feedthrough conductivepathways such that electrical current or sensing signals can travelbetween the AIMD pulse generator and the distal electrodes of animplanted lead in contact with body tissue. For simplicity, theexemplary embodiment of FIG. 30 illustrates only two feedthroughconductive pathway connection points, each feedthrough conductivepathway point connectable from either an AIMD hermetically sealedfeedthrough or an AIMD hermetically sealed feedthrough comprising afeedthrough filter or an EMI filter circuit board (not shown) to an AIMDcomponent, which, in the embodiment of FIG. 30, is an AIMD activeelectronic circuit board 106, The AIMD active electronic circuit board106 illustrated comprises two electrically conductive terminal pin halfpads 170 b, each terminal pin half pad mechanically and electricallyattached to circuit board landing pads 104 of the circuit trace 105.Such terminal pin half pads 170 b are alternatively attachable tocircuit board pad, a circuit board via hole, a circuit board land, or acircuit trace. Such terminal pin half pads 170 b could be made of anyelectrically conductive material as the terminal pin half pads 170 breside inside of the hermetically sealed AIMD casing 32, therefore donot need to be biocompatible. The terminal pin half pads 170 billustrated are routed to other AIMD circuitry within the AIMD 12. Theterminal pin half pads 170 b residing on the AIMD active electroniccircuit board 106 positions the AIMD active electronic circuit boardbeneath the terminal pins 18 such that a top capture pad 172 isattachable to the AIMD active electronic circuit board 106 usingfasteners 174 as shown. The top capture pad 172 comprises an insulativeframe with two electrically conductive terminal pin half pads 170 aInsulated from each other. Illustrated is a bipolar system, but it isunderstood that the embodiment of FIG. 30 could be unipolar, quad polar,or “n” polar. Referring once again to FIG. 30, the diameter of terminalpin 18 would typically be slightly larger than the diameter formed whenthe terminal pin half pad 170 a and the terminal pin half pad 170 bengages terminal pin 18. When the fasteners 174 screwed in so that thetop capture pad 172 is attached to the AIMD active electronic circuitboard 106, a small gap between the terminal pin half pad 170 a and theterminal pin half pad 170 b surrounding the terminal pin 18 is present.As such, the terminal pin 18 is captured such that longitudinal movementis prevented, resulting in a robust mechanical and electricalattachment. In one embodiment, the terminal pin half pads 170 a and 170b could be any suitably electrically conductive material, includinginsulative materials coated or plated with an electrically conductivematerial as previously disclosed herein. During the laser welding of theAIMD can halves 112, 114, as previously disclosed, may exhibit somedegree of terminal pin longitudinal movement so that undo stresses andstrains cannot build up if expansion and contraction occurs between thecan halves and the circuit board due to mismatch of thermal coefficientsof expansion. Thermal coefficient of expansion mismatch may also causeresidual stresses and strains during laser welding of the ferrule 26,the AIMD can half 112 and the AIMD can half 114, as inhomogeneoustemperature distributions may arise, potentially causing a terminal pin18 to expand and push against the terminal pin half pads 170 a and 170b.

FIG. 30A is very similar to FIG. 30, except that in the embodiment ofFIG. 30A, the top capture pad 172 is staggered to accommodate dualin-line terminal pin configurations. As illustrated, some of theterminal pin half pads 170 b are shorter and other terminal pin halfpads 170 b″ are taller than illustrated in FIG. 30. Such heightvariations of the terminal pin half pads are made so that each one ofthe staggered terminal pins 18 hermetically sealed to the insulator 28are appropriately spatially aligned within their respective terminal pinhalf pads 170 b and 170 b″ so that the top capture pad 172 can befastened to the AIMD active electronic circuit board 106, therebycapturing each terminal pin 18 between the terminal pin half pads 170 bor 170 b″ and the top capture pad 172.

FIG. 31 is a cross-sectional view of an exemplary bus-bar-like terminalpin connector embodiment. This terminal pin connector embodimentillustrates two terminal pins 18 each uniquely captured by the terminalpin connector, two fastening configurations for attaching the topcapture pad 172 to an AIMD active electronic circuit board 106, and auniquely configured top capture pad 172. Referring now to the fasteners174, illustrated are simple slotted screws. Alternatively, the fasteners174 can be selected from the group consisting of allen screws, Torxscrews, hex screws, star screws and combinations thereof. The fasteners174 are optionally fastenable using a torque wrench.

Referring to the embodiment of the fastening configuration on theright-hand side of FIG. 31, illustrated is a female screw threadreceptacle 176 affixed to the surface of the AIMD active electroniccircuit board 106, the female screw thread receptacle in this embodimentis shown positioned at, near or adjacent a terminal pin half pad 172 b.The top capture pad 172 comprises a via hole on the right-hand side thatis spatially aligned with a threaded opening of the female screw threadreceptacle 176. When the fastener 174 is inserted through the via holeof the top capture pad 172 and into the threaded opening of the femalescrew thread receptacle 176, the top capture pad 172 is fastened to theAIMD active electronic circuit board 106. As such, this optionalfastening configuration enables AIMD assembly such that an AIMD casinghalf 114 (not shown) can be positioned to physically contact the surfaceof the fastener 174 so that the fastener 174 cannot come loose or backout from the female screw thread receptacle 176.

Referring to the embodiment of the fastening configuration on theleft-hand side of FIG. 31, the top capture pad 172 is illustratedstepped down, wherein the step portion 173 of the top capture pad 172 onthe left-hand side comprises a via hole. When the top capture pad 172 isseated on the AIMD active electronic circuit board 106, the via hole isspatially aligned with a threaded opening of the AIMD active electroniccircuit board 106. When the fastener 174 is inserted through the viahole of the step portion 173 of the top capture pad 172 and into thethreaded opening of the AIMD active electronic circuit board 1068, thestep portion 173 of the top capture pad 172 is fastened to the AIMDactive electronic circuit board.

Referring to the embodiment on the left-hand side for capturing aterminal pin 18, illustrated are two electrically conductive terminalpin pad halves, a terminal pin pad half 170 a attached to the topcapture pad 172 and a terminal pin pad half 170 b attached to the AIMDactive electronic circuit board 106. When the top capture pan 172 isfastened, terminal pin 18 is captured by terminal pin pad halves 170 aand 170 b similarly to the embodiment of FIG. 30.

Referring to the embodiment for capturing a terminal pin 18 to the leftof the female screw thread receptacle 176 of FIG. 31, illustrated is anelectrically conductive terminal pin pad half 170 b attached to the AIMDactive electronic circuit board 106 and an insulator pad 175monolithically extending from the top capture pad 172. The insulator pad175, which is formed during the manufacturing of the top capture pad172, is configured to mate with a portion of the diameter of theterminal pin 18. When the top capture pan 172 is fastened, terminal pin18 is captured by terminal pin pad half 170 b and the insulator pad 175.

Referring to the exemplary embodiment of the top capture pad 172 of FIG.31, it is noted herein that variations of the top capture pad 172 can bemade to satisfy the specific needs of an application. For example, it iscontemplated that step portion 173 of the top capture pad 172 couldoptionally comprise a compliant spring-like material. The step portion173 of the top capture pad 172 could also optionally be angled, orthinner than the overall thickness of the top capture pad 172, orcurved, in order to apply less force to one or more terminal pins 18 orto flex so as to accommodate varying tolerancing or to permit somedegree of longitudinal movement should mismatches of coefficient ofexpansion exist during thermal assembly processes. The top capture pad172 may comprise one of only terminal pin half pads, only monolithicinsulator pads, or combinations thereof. The top capture pad 172 may beinsulative only or selectively electrically conductive. While theembodiments of FIG. 31 are exemplary, the embodiments are not meant tobe limiting. Accordingly, a specific configuration of a top capture pad172 may comprise one or more of any of the embodiments disclosed withinthe present application.

FIG. 32 illustrates a cross-sectional view of yet another embodiment ofan exemplary bus-bar-like terminal pin connector. Illustrated arecompliant terminal pin half pads 170 a′ and 170 b′ in accordance withthe definition of the term “compliant” previously defined herein. In thecompliant embodiment of FIG. 32, has elastic resilience permittinglongitudinal movement of terminal pins 18 if needed. As previouslydisclosed for other compliant components herein, the compliant terminalpin half pads 170 a′ and 170 b′ may be plated to enhance a particularproperty of the compliant terminal pin pads. For example, plating may beprovided to enable electrical conductivity, increase strength anddurability, allow solderability, improve electrical conductivity,increase surface hardness, provide wear resistance, impart anti-gallingproperties, afford antifriction properties, offer movement lubricity, orincrease friction to impart resistance to movement or to enhance grip.The plating may be of the same materials and by the same processespreviously disclosed herein.

Referring once again to FIG. 32, both terminal pin half pads areillustrated being compliant terminal pin half pads 170 a′ and 170 b′,however, it is contemplated that one or the other terminal pin half padsmay be compliant while its corresponding terminal pin half pad is notcompliant. Furthermore, it is irrelevant as to whether the compliantterminal pin half pad is attached to the top capture pad 172 or the AIMDactive electronic circuit board 106, need not be at the top and bottom.In other words, the upper terminal pin half pad could be a compliantterminal pin half pads 170 a′ and the bottom terminal pin half pad couldbe the non-compliant terminal pin half pad 170 b of FIG. 31.

Referring to the fasteners, it noted herein that the fasteners 174 ofFIGS. 31 and 32 are merely illustrative. While the fasteners of FIG. 32are self-tapping or machine screw fasteners, any type of fastener may beused that preserves removability of defective AIMD components forreplacement or reworked and re-installation. Additionally, in the spiritof removability, the fasteners disclosed herein may further compriselock washers, a removable LOC TITE, nylocks or other such componentsthat employ special design to ensure a snug and secure attachment whilestill remaining removable. Such component additions to a fastener canprevent a fastener from backing out, inadvertent or componentmishandling detachments, and compliance to industry shock, vibration anddrop test requirements. It will be appreciated that a threaded openingas illustrated may instead be a tapped hole. Alternatively, a threadedopening may be replaced by a threaded post, a threaded insert, or athreaded connector housing of an AIMD component without departing fromthe spirit and the scope of the subject matter of the presentapplication.

Referring once again to FIGS. 31 and 32, it is understood that the topcapture pad 172 can be insulative and incorporate an electricallyconductive terminal pin half pad 170 a or an electrically conductivecompliant terminal pin pad 170 a′; or, the top capture pad 172 couldcomprise an electrically insulative top capture pad 170 or anelectrically insulative compliant terminal pin pad 170 a′. Electricalconnection can be made to terminal pin 18 by only contacting theterminal pin 18 to the terminal pin half pad 107 b or the compliantterminal pin half pad 107 b′. Electrically insulative terminal pin halfpads may be integral to the top capture pad 172 or separately attachedto the top capture pad 172. An insulating material may be selected fromthe group consisting of polyimide, acrylic, glass, fiberglass, rubber,polyester, polyether imide, polytetrafluoroethylene, polyethylene,polyetheretherketone (PEEK), polyethylene napthalate, polyvinyl chloride(PVC), fluoropolymers, copolymers, ceramic, a laminate, a resin, papers,films, foams, silicone, sponge, rubber, soft ceramic-filled silicone, asilicone coated fabric or mesh, a silicone foam, an open-cell foam suchas, but not limited to, a polyurethane, a reticulated polyurethane foam,a closed cell foam such as, but not limited to, polyethylene, across-linked polyethylene foams, or combinations thereof.

Generally regarding electrical connection to terminal pin 18, someterminal pin materials are subject to oxidation over time. If a terminalpin 18 is pre-disposed to oxidation, the terminal pin may require a“tin-dip” or a plating such that a robust electrical connection can beconsistently achieved. Any of the previously disclosed materials may beused in accordance with the teachings herein regarding whether theterminal pin resides on the body fluid side or on the device side of theAIMD.

The terminal pin half pads 170 b and 170 b′, as illustrated in FIGS. 31and 32, are readily populated by robots during population of othercomponents on the AIMD active circuit board 106. The terminal pin halfpads may be attached to one of a circuit board landing pad, a circuittrace, a bond pad, a circuit board land by currently availableattachment methods, including robotic dispensing of BGA (ball gridarray), which can encompass solder or electrically conductivethermal-setting adhesives and the like.

FIG. 33 illustrates an embodiment of a bus-bar-like terminal pinconnector for use with an AIMD header block. An AIMD header block 118 ispreviously described in FIGS. 10, 12 and 13. Referring once again toFIG. 33, illustrated are terminal pin half pads 170 b attached to eachelectrical conductor 122 residing within a formed insulating structure120 of an AIMD header block 118 (not shown). In the embodiment of FIG.33, the terminal pin half pads 170 b must be electrically conductive,biocompatible, biostable and non-toxic. In an embodiment, the terminalpin half pads 170 b would be of the same material as the electricalconductors 122. In an embodiment, the terminal pin half pads would be adifferent material than the electrical conductors 122. The terminal pinhalf pads of FIG. 33 may be metallic and therefore, electricallyconductive or may alternatively be an electrically insulating materialthat has an electrically conductive or a metallic coating on itssurfaces. The terminal pin half pads 170 b of FIG. 33 may furthercomprise any of the biocompatible, biostable and non-toxic materialspreviously described for the electrical conductor of FIGS. 12 and 13.Similarly, the terminal pin half pads 170 b of FIG. 33 may furthercomprise the biocompatible, biostable and non-toxic insulating materialsand electrically conductive or metallic coatings also previouslydisclosed herein for the various AIMD components disposed on the bodyfluid side of the AIMD. Similar to the terminal pin half pads disclosedfor the device side of the AIMD, the terminal pin half pads 170 b ofFIG. 33 are designed to capture terminal pins 18 passing through theinsulator 28 of the AIMD hermetically sealed feedthrough 14 extending tothe body fluid side of the AIMD. In FIG. 33, the top capture pad 172would be entirely insulative and is fastened to the header block usingfasteners 174, as shown. It is contemplated that the fasteners 174 canbe selected from the group consisting of allen screws, Torx screws, hexscrews, star screws and combinations thereof. The fasteners 174 may bescrewed directly into the formed insulation structure 120 (not shown) ofthe AIMD header block 118, or to vias in the electrical conductor 122 asillustrated.

Referring once again to FIG. 33, it is contemplated that the terminalpin half pads 170 b could be eliminated and instead, the ends of theelectrical conductors 122 could be formed into a semi-circularconfiguration for engaging with the terminal pin 18. In this embodiment,the conductors 122 may comprise an electrically conductive biocompatiblecoating or plating so that, when the top capture pad 172 is affixed andcompressed against terminal pins 18, a low resistance electricalconnection be made. The electrically conductive biocompatible coating orplating may be any one of the biocompatible electrically conductivematerials previously disclosed herein, which may be applied by any ofthe processes also previously disclosed herein.

Referring once again to FIG. 33, it is understood that other componentshaving threaded holes could be added to or within the AIMD header block118 such that fasteners 174 could be used to fasten the top capture pad172 to the AIMD header block. It is also understood that the entire topcapture pad 172 and the terminal pin half pads 170 a could all beinsulative, offering a cost-effective attachment option. Referring onceagain to FIG. 33, of importance is that the terminal pin half pads 170 bbe electrically conductive. This would mean that electrically conductingmaterials subject to surface oxidation like tantalum, niobium ortitanium must be coated or plated with a suitable higher conductivitypreferably oxide-resistant material, such as pure gold or pure rhodium(which are also biocompatible). In an embodiment, the terminal pin halfpads 170 b could be made of a biocompatible highly conductive material,such as pure platinum or gold; however, these may be prohibitivelyexpensive. The terminal pin half pads 170 b may comprise any of thebiocompatible materials previously disclosed herein. The terminal pinhalf pads 170 b may comprise a coating or a plating comprising thebiocompatible materials and application processes also previouslydisclosed herein. The coating or plating may be applied to increasestrength and durability, allow solderability, or to improve electricalconductivity. Additionally, the terminal pin half pads 170 b maycomprise a gold flash over any plated material.

FIG. 34 illustrates an embodiment, wherein clips 200 or 200′ have beenpopulated onto an electrical connection pad 104 of an AIMD activeelectronic circuit board 106. Clips 200 and 200′ are compliant clips inaccordance with the definition of the term “compliant” previouslydefined herein. As clips 200, 200′ are on the device side inside thehermetically sealed AIMD casing 32, sad clips 200, 200′ need not bebiocompatible, and could comprise any elastically resilient material,for example, beryllium copper or the like. The clips 200, 200′ in theembodiment of FIG. 34 may be populated by a circuit board manufacturingrobot along with all the other circuit board components (such as themicroprocessor and other components not shown). Additionally, a roboticdispensing of a BGA dot, which could be a solder, or a solder paste, ora thermal-setting conductive adhesive dot, could also be roboticallydispensed onto the electrical connection pad 104 for clip attachment itis contemplated that during manufacturing, the solder would be reflowed,or the conductive epoxy would be cured, thereby firmly affixing clips200 and 200′ to the electrical connection pad 104 of the AIMD activeelectronic circuit board 106. In any of the embodiments disclosed in thepresent application, a circuit board electrical connection pad 104 mayeither be part of a circuit trace 105 as shown or comprise a circuitboard land connected to one or more internal circuit traces (not shown)or may even directly connected to an electronic component (not shown).

The electrical connection pad 104 and circuit trace 105 are manufacturedusing known circuit board manufacturing techniques. The electricalconnection pad 104, also known as a bond pad, may further comprise anaffixed metal pad, such as a Kovar pad and the like. Affixing a Kovarpad (not shown) to the electrical connection pad 104 that is gold platedcan provide high surface area for soldering to the electrical connectionpad 104 or could facilitate laser welding or brazing of the clips 200,200′ to the electrical connection pad 104.

Referring once again to FIG. 34, the compliant clips 200, 200′ can beplated or coated with a suitable material, such as gold or rhodium,which are high conductivity materials. Rhodium also has the advantage ofwear resistant thereby allowing multiple terminal pin 18 insertions andretractions.

FIG. 34A is a sectional view taken along lines 34A-34A of FIG. 34illustrating an alternative embodiment of clip 200′. In the embodimentof FIG. 34A, an electrically conductive post 202 is added to the clip200′ of FIG. 34. The clip 200′ of FIG. 34A is mechanically andelectrically attached to the AIMD active electronic circuit board 106 byinserting the post 202 of the clip 200′ into to a via hole 109 of theAIMD active electronic circuit board 106. An electrical connection 206electrically connects the post 202 to the metallization 208 of the viahole 109, the electrical connection 206 firmly securing the post 202 andthe clip 200′ to the AIMD active electronic circuit board 106. The post202 may be affixed to the clip 200′ by co-forming as one piece, or thepost 202 and the clip 200′ may be connected 204 by welding, brazing,soldering, or an equivalent process. The clip 200′ and post 202 may alsobe made using 3-D printing processing. The post 202 could be of the samematerial as the clip 200′ or a material different from the clip 200′.Clip 200′ with attached post 202 may optionally be coated or plated aspreviously disclosed herein. As clip 200′ is inside the AIMD, neitherthe clip 200′, the coating or the plating need to be biocompatible.AIMDs must satisfy shock, vibration and drop test requirements asdescribed by ISO 14708-1, which sets the general standards for allimplantable medical devices, and the specific shock, vibration, and droptest requirements of ISO 14708-2 and ISO 14708-6, which sets theparticular requirements for implantable cardiac pacemakers andimplantable cardioverter defibrillators including an impact requirement(the example typically describing impact being an AIMD implanted withina pectoral pocket getting hit by a baseball). The embodiment of FIG. 34Aoffers a robust option for meeting such requirements.

Referring again to FIG. 34A, illustrated is an electrical connection 206of the clip 200′ with post 202 to an electrically conductive circuitboard via hole 109, which typically comprises an electrically conductiveplating, metallization, eyelet and the like. The via hole 109 of FIG.34A illustrates an eyelet 208. The electrical connection 206 between theclip 200′ with post 202 and the eyelet 208 may be a reflowed solder or acured thermal-setting conductive adhesive. It is contemplated thatelectrical connection 206 could also be a thermal-setting conductiveepoxy or even a low temperature braze.

The design of the compliant clip 200′ of FIGS. 34 and 34A is importantin that the spring rate and the curvature of the wings 210 of the clip200′ must be such that the terminal pin 18 can be pressed into and thenfirmly gripped by the wings 210. The insertion of terminal pin 18spreads the wings 210 of the clip 200′, as shown in FIG. 34A, so thatthe wings 210 open enough to snugly seat the terminal pin 18 within thewings 210 of the clip 200′ and positioned and firmly gripped as shown bydashed circle 18′. The design considerations above also apply to clip200 of FIG. 34.

Referring once again to FIGS. 34 and 34A, it will be appreciated thatthe plating or coating that may optionally be placed on the clips 200and 200′ is also important. For example, if the coating or plating arelubricious or smooth, insertion and retraction of the terminal pin 18 isfacilitated. Likewise, if the coating and the plating is coarse,insertion and retraction of the terminal pin 18 is impeded. Accordingly,in accordance with the present invention, the surface roughness of thecoating on the clips 200, 200′ can be adjusted to a desired push andpull force. For example, the coating could be deliberately placed down,shot in or plasma-etched to provide a relatively higher degree ofsurface roughness to tailor tolerance to shock, vibration, drop andimpact loads such that the terminal pin 18 does not undesirably detachfrom the clip 200, 200′.

Referring to FIG. 34B, the clip 200′ has been co-formed during astamping process to include a post 202′. This embodiment allows the dualwings 210, 210′ to be formed at the same time as the opposing wing 210″and at the same time as the post 202′. It will be appreciated that thepost 202′ of FIG. 34B, is configured for insertion into and connectionto the circuit board via hole 109 in the same manner as disclosed forpost 202 of FIG. 34A.

FIG. 34C illustrates an embodiment similar to FIG. 34B, except that thepost 202′ of the embodiment of FIG. 34C comprises a curved structure sothat when the post 202′ is inserted into the via hole 109 in the samemanner as disclosed for post 202 of FIG. 34A, the curved structure ofthe post 200′ compresses against opposing sidewalls of the via hole 109such that the post 202′ is held firmly in place. As such, the firmholding in place of the clip 200′ by the curved post 202′ facilitatesapplication and flow of a solder, a thermal-setting conductive adhesive,a thermal-setting epoxy, or a braze during a reflow, a curing or abrazing process that forms the electrical connection 206 between theclip 200′ with curved post 202′ and electrically conductive via hole 109of the AIMD active electronic circuit board 106. Those skilled in theart will understand that, when a very low weight structure, such as clip200′ and post 202′, sits in liquifying solder or braze or is in adispensed liquid adhesive or epoxy, there is a tendency for the entirestructure to float in the liquid. The unique curving to the post 202′ ofclip 200′ of the embodiment of the present application such that thepost is mechanically ‘clipped’ (in other words pinned) to the via hole,thereby preventing the clip 200′ from floating or moving during reflow,brazing, or curing processes, provides an effective economicalconnection option, which otherwise would require more costly andtime-consuming production fixturing, such as pogo springs that push downon the structure during the attachment process. It will be appreciatedthat the clip 200′ with the curved post 202′ of FIG. 34C, is co-formedin the same manner as disclosed for FIG. 34B. It will also beappreciated that curved post 202′ is inserted into the circuit board viahole 109 in the same manner as disclosed for post 202 of FIG. 34A.

FIG. 34D illustrates an embodiment of clip 200′ having a single wing 210instead of the double wings 210, 210′ of the clip 200′ of FIGS. 34B and34C. The single wing 210 of FIG. 34D is opposed by a larger wing 210′″.The post 202′ of the clip 200′ of FIG. 34D comprises the curvedstructure of FIG. 34C. It will be appreciated that the curved post 202′of the embodiment of FIG. 34D provides another effective economicalconnection option in the same manner as disclosed for the curved post202′ of FIG. 34C. It will also be appreciated that the clip 200′ withthe curved post 202′ of FIG. 34D, is co-formed in the same manner asdisclosed for FIG. 34B and is inserted into the circuit board via hole109 in the same manner as disclosed for post 202 of FIG. 34A.

FIG. 34E illustrates an embodiment of clip 200′ that is very similar tothe clip 200′ of FIG. 34D, except that in the embodiment of FIG. 34E,the positions of the single wing 210 and the post 202′ are reversedcompared to the positions of the single wing 210 and the post 202′ ofFIG. 34D, and the post 202′ of FIG. 34E has a radius of curvature 212,as shown, instead of having a curved structure as shown in the curvedpost 202′ of FIG. 34D. The radius of curvature 212 of the post 202′ ofclip 200′ of FIG. 34E is carefully designed such that it is slightlylarger than the radius of curvature of the via hole 109 of the AIMDactive electronic circuit board 106 of FIG. 34A. The slightly largerradius of curvature 212 of the post 202′ of FIG. 34E allows insertion ofthe radiused post 202′ into the via hole 109 such that the radiused post202′ compresses against opposing sidewalls of the via hole 109 holdingthe clip 200′ firmly in place. As such, the firm holding in place of theclip 200′ by the radiused post 202′ facilitates application and flow ofa solder, a thermal-setting conductive adhesive, a thermal-settingepoxy, or a braze during a reflow, a curing or a brazing process thatforms the electrical connection 206 between the clip 200′ with radiusedpost 202′ and electrically conductive via hole 109 of the AIMD activeelectronic circuit board 106 similarly to the curved post 202′ of FIGS.34C and 34D. It will be appreciated that the radiused post of theembodiment of FIG. 34E provides yet another effective economicalconnection option in the same manner as disclosed for the curved post ofFIGS. 34C and 34D. It will also be appreciated that the clip 200′ withthe radiused post 202′ of FIG. 34E, is co-formed in the same manner asdisclosed for FIG. 34B and is inserted into the circuit board via hole109 in the same manner as disclosed for post 202 of FIG. 34A.

Referring once again to FIGS. 34 through 34E, the material ofconstruction of any of the stamped or co-formed clips of FIGS. 34through 34E could be any suitable compliant elastically resilientmaterial disclosed herein. Additionally, any of the clips of FIGS. 34through 34E could comprise an insulating material instead of anelectrically conductive material. Suitable insulating materials are hightemperature (have melting and deflection temperatures aboveapproximately 204° C.), high strength materials and capable ofwithstanding a sustained high temperature soldering process withoutdeforming. There are a wide variety of polymers and plastics that canwithstand high temperatures. Insulating materials may be selected fromthe group consisting of acrylonitrile butadiene styrene (ABS),polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), polyamide-imide(PAI), polyether ether ketone (PEEK™), polyaryletherketone (PAEK),stereolithography (SLA) resin, polyetherimide (PEI), polyamide (PI),polyamide (PA), polyphenylsulfone (PPSU), polysulfone (PSU),polybenzimidazole (PBI), thermoplastic polyimide (TPI), polyethersulfone(PES), polyether ketone (PEK), polyphenylen sulfide (PPS),polychlorotrifluoroethylene (PCTFE), ethylene chlorotrifluoroethylene(ECTFE), polyvinylidene fluoride (PVDF), fluoropolymer (FP), andcombinations thereof. Insulating materials may also be selected from thegroup consisting of Teflon®, Rulon®, Torlon®, Ultem®, Vespel®, Radel®,Celazole®, molded plastics, 3 dB plastics, among others. Such clipscomprising insulating material would require an electrically conductivecoating or plating. The electrically conductive coating or plating maybe any one of the electrically conductive materials previously disclosedherein, which may be applied by any of the processes also previouslydisclosed herein. It will also be appreciated that a plating or coatingcould be applied to clip 202′ to impart supplemental properties also aspreviously disclosed herein. It is understood that the embodiments shownin FIGS. 34 through 34E are low cost options for electrically connectingterminal pins 18 to AIMD components.

As defined herein and used throughout, an AIMD circuit board 106 is acircuit board enclosed within the hermetically sealed AIMD casing 32that contains active electronic circuits, including, in most cases, amicroprocessor among many other components. An AIMD either has a primarybattery or a secondary (rechargeable) battery that drives the circuitboard or a that drives the circuit board electronics or another sourceof energy, such as an energy harvesting mechanism from body motions,thermal energy or externally induced ultrasonic energy and the like.Hence, an AIMD circuit board 106 is an active electronic circuit boardand not a circuit board containing only passive electronic components.On the other hand, an EMI filter circuit board is a circuit board thatmay comprise MLCCs, X2Y attenuators or flat-thru capacitors placed on,near, adjacent or slightly away from an AIMD hermetic seal, which isdisposed in an opening of the AIMD casing. So, there is a cleardistinction between a removable AIMD active electronic circuit board anda removable EMI filter circuit board again, as the AIMD activeelectronic circuit board has at least one active electronic component.

While particular aspects of the present subject matter described hereinhave been shown and described, it will be apparent to those skilled inthe art that, based upon the teachings herein, changes and modificationsmay be made without departing from the subject matter described hereinand its broader aspects and, therefore, the appended claims are toencompass within their scope all such changes and modifications as arewithin the true spirit and scope of the subject matter described herein.Furthermore, while this specification contains many specifics, theseshould not be construed as limitations on the scope of what may beclaimed, but rather as descriptions of particular implementations of thesubject matter. Certain features that are described in thisspecification in the context of separate embodiments can also beimplemented in combination in a single embodiment. Conversely, variousfeatures that are described in the context of a single embodiment canalso be implemented in multiple embodiments separately or in anysuitable sub-combination. Moreover, although features may be describedabove as acting in certain combinations and even initially claimed assuch, one or more features from a claimed combination can in some casesbe excised from the combination, and the claimed combination may bedirected to a sub-combination or variation of a sub-combination.

What is claimed is:
 1. A circuit board connector assembly, comprising:a) a circuit board having at least one electrical circuit; and b) aterminal pin connector, comprising: i) a connector housing comprising analignment flange having an inner surface that tapers downwardly andinwardly from a proximal opening to an electrically conductive connectorhousing sidewall, the connector housing sidewall defining a housingopening extending along a longitudinal axis, wherein the connectorhousing is electrically connected to the at least one electrical circuitof the circuit board; and ii) at least one electrically conductiveconnector prong supported by and angled from the connector housingsidewall toward the longitudinal axis of the housing opening.
 2. Thecircuit board connector assembly of claim 1, wherein the at least oneconnector prong comprises at least two connector prongs, both connectorprongs angled toward the longitudinal axis of the housing opening. 3.The circuit board connector assembly of claim 1, wherein at least one ofthe group of a solder, a braze, an electrically conductive adhesive, anda weld electrically connects the connector housing of the terminal pinconnector to the at least one electrical circuit of the circuit board.4. The circuit board connector assembly of claim 1, wherein theconnector housing of the terminal pin connector comprises a clip basesupported in the housing opening by the connector housing sidewall, andwherein the clip base defines a through-bore in open communication withthe housing opening, the clip base supporting the at least oneelectrically conductive connector prong that angles inwardly toward thelongitudinal axis of the housing opening.
 5. The circuit board connectorassembly of claim 1, wherein the connector housing sidewall comprises atleast one planar surface attached to the circuit board.
 6. The circuitboard connector assembly of claim 5, wherein the circuit board has aperipheral edge, and wherein the alignment flange extends outwardlybeyond the at least one planar surface of the connector housing sidewallso that with the planar surface attached to the circuit board, thealignment flange overhangs the peripheral edge of the circuit board. 7.The circuit board connector assembly of claim 4, wherein the clip basehas a clip base inner surface that tapers downwardly and inwardly froman inner surface of the connector housing sidewall toward thelongitudinal axis of the housing opening.
 8. The circuit board connectorassembly of claim 1, wherein the alignment flange resides adjacent totwo exterior planar surfaces of the connector housing sidewall.
 9. Thecircuit board connector assembly of claim 8, wherein the two exteriorplanar surfaces of the connector housing sidewall are oriented normal toeach other.
 10. An active implantable medical device (AIMD), comprising:a) a casing of the AIMD, wherein the AIMD casing houses a circuit board,the circuit board having at least one electrical circuit; b) a firstterminal pin connector, comprising: i) a first connector housingcomprising an electrically conductive first connector housing sidewalldefining a housing opening extending along a first longitudinal axis,wherein the first connector housing is electrically connected to the atleast one electrical circuit of the circuit board; and ii) at least oneelectrically conductive connector prong supported by the connectorhousing sidewall in the housing opening, the connector prong angledtoward the first longitudinal axis of the housing opening; c) afeedthrough, comprising: i) an electrically conductive ferrulecomprising a ferrule opening, wherein the ferrule is sealed in anopening in the AIMD casing; ii) an insulator hermetically sealed to theferrule in the ferrule opening, wherein the insulator has an insulatorbody fluid side opposite an insulator device side, the insulator bodyfluid and device sides residing outside and inside the AIMD casing,respectively, and wherein at least one insulator passageway extendsthrough the insulator; and iii) an electrically conductive terminal pinhermetically sealed to the insulator in the insulator passageway,wherein a device side portion of the terminal pin extends outwardlybeyond the insulator device side, and d) wherein the terminal pinconnector is configured to allow multiple insertions and retractions ofthe device side portion of the feedthrough terminal pin into and out ofthe housing opening with the at least one connector prong angled towardthe first longitudinal axis of the housing opening being accordinglycontacted to and uncontacted from the device side portion of theterminal pin to thereby selectively establish electrical continuity fromthe terminal pin of the feedthrough to the at least one electricalcircuit of the circuit board.
 11. The AIMD of claim 10, wherein the atleast one connector prong comprises at least two connector prongs, bothconnector prongs angled toward the first longitudinal axis of thehousing opening, and wherein each connector prong contacts andcompresses against the device side portion of the feedthrough terminalpin extending outwardly beyond the insulator device side insides theAIMD casing.
 12. The AIMD of claim 10, wherein at least one of the groupof a solder, a braze, an electrically conductive adhesive, and a weldelectrically connects the first connector housing of the first terminalpin connector to the at least one electrical circuit of the circuitboard.
 13. The AIMD of claim 10, wherein the first connector housing ofthe first terminal pin connector comprises a clip base supported in thehousing opening by the connector housing sidewall, and wherein the clipbase defines a through-bore in open communication with the housingopening, the clip base supporting the at least one electricallyconductive connector prong that angles inwardly toward the firstlongitudinal axis of the housing opening, and wherein with the deviceside portion of the feedthrough terminal pin extending outwardly beyondthe insulator device side being disposed in the through-bore of the clipbase, the at least one connector prong contact the feedthrough terminalpin.
 14. The AIMD of claim 10, wherein the first connector housingsidewall comprises at least one planar surface attached to the circuitboard.
 15. The AIMD of claim 10, wherein: a) the circuit board furtherhas at least one ground electrical path; b) at least one ground pin iselectrically connected to the ferrule; and c) the AIMD further comprisesat least one ground pin connector, comprising: i) a second connectorhousing comprising an electrically conductive second connector housingsidewall defining a second housing opening extending along a secondlongitudinal axis, wherein the ground pin connector housing iselectrically connected to the at least one ground electrical path of thecircuit board; and ii) at least one electrically conductive ground pinprong supported by the second connector housing sidewall in the secondhousing opening, the ground pin connector prong angled toward the secondlongitudinal axis of the second housing opening to contact and compressagainst the at least one ground pin, iii) wherein the ground pinconnector is configured to allow multiple insertions and retractions ofthe at least one ground pin into and out of the second housing openingwith the at least one ground pin connector prong being accordinglycontacted to and uncontacted from the ground pin electrically connectedto the ferrule.
 16. The AIMD of claim 10, further including afeedthrough capacitor comprising at least one active electrode plateinterleaved in a capacitive relationship in a capacitor dielectric withand at least one ground electrode plate, wherein the active electrodeplate is electrically connected to the feedthrough terminal pin and theat least one ground electrode plate is electrically connected to theferrule.
 17. The AIMD of claim 15, wherein: a) the circuit board has aperipheral edge; b) the first connector housing comprises a firstalignment flange having an inner surface that tapers downwardly andinwardly from a proximal opening to the electrically conductive firstconnector housing sidewall; c) the second connector housing comprises asecond alignment flange having an inner surface that tapers downwardlyand inwardly from a proximal opening to the electrically conductivesecond connector housing sidewall; and d) the first alignment flange ofthe first connector housing extends outwardly beyond a first sidesurface of the first connector housing sidewall and the second alignmentflange of the second connector housing extends outwardly beyond a secondside surface of the second connector housing sidewall so that with thefirst and second side surfaces attached to the circuit board, the firstand second alignment flanges overhang the peripheral edge of the circuitboard.
 18. The AIMD of claim 13, wherein the clip base has a clip baseinner surface that tapers downwardly and inwardly from an inner surfaceof the connector housing sidewall toward the longitudinal axis.
 19. TheAIMD of claim 10, wherein the first alignment flange resides adjacent totwo exterior planar surfaces of the first connector housing sidewall.20. The AIMD of claim 19, wherein the two exterior planar surfaces ofthe first connector housing sidewall are oriented normal to each other.21. The AIMD of claim 10, wherein the first connector housing comprisesa first alignment flange having an inner surface that tapers downwardlyand inwardly from a proximal opening to the electrically conductivefirst connector housing sidewall.
 22. The AIMD of claim 15, wherein thesecond connector housing comprises a second alignment flange having aninner surface that tapers downwardly and inwardly from a proximalopening to the electrically conductive second connector housingsidewall.
 23. A circuit board connector assembly, comprising: a) acircuit board having at least one electrical circuit; and b) a terminalpin connector, comprising: i) a connector housing comprising analignment flange having an inner surface that tapers downwardly andinwardly from a proximal opening to an electrically conductive connectorhousing sidewall, the connector housing sidewall defining a housingopening extending along a longitudinal axis, wherein the connectorhousing is electrically connected to the at least one electrical circuitof the circuit board; and ii) at least two electrically conductiveconnector prongs supported by and extending from the connector housingsidewall to connector prong distal ends residing in the housing opening,the connector prongs angled toward the longitudinal axis of the housingopening.
 24. An active implantable medical device (AIMD), comprising: a)a casing of the AIMD, wherein the AIMD casing houses a circuit board,the circuit board having at least one electrical circuit; b) a firstterminal pin connector, comprising: i) a first connector housingcomprising an electrically conductive first connector housing sidewalldefining a housing opening extending along a first longitudinal axis,wherein the first connector housing is electrically connected to the atleast one electrical circuit of the circuit board; and ii) at least oneelectrically conductive connector prong supported by the connectorhousing sidewall in the housing opening, the connector prong angledtoward the first longitudinal axis of the housing opening; c) afeedthrough, comprising: i) an electrically conductive ferrulecomprising a ferrule opening, wherein the ferrule is sealed in anopening in the AIMD casing; ii) an insulator hermetically sealed to theferrule in the ferrule opening, wherein the insulator has an insulatorbody fluid side opposite an insulator device side, the insulator bodyfluid and device sides residing outside and inside the AIMD casing,respectively, and wherein at least one insulator passageway extendsthrough the insulator; and iii) an electrically conductive terminal pinhermetically sealed to the insulator in the insulator passageway,wherein a device side portion of the terminal pin extends outwardlybeyond the insulator device side, and d) wherein the terminal pinconnector is configured to allow at least one insertion and retractionof the device side portion of the feedthrough terminal pin into and outof the housing opening with the at least one connector prong angledtoward the first longitudinal axis of the housing opening beingaccordingly contacted to and uncontacted from the device side portion ofthe terminal pin to thereby selectively establish electrical continuityfrom the terminal pin of the feedthrough to the at least one electricalcircuit of the circuit board.
 25. The AIMD of claim 24, wherein thefirst connector housing sidewall comprises at least one planar surfaceattached to the circuit board.